BIOPARTICLE ISOLATION AND THERAPEUTIC APPLICATION THEREOF
20190040093 ยท 2019-02-07
Assignee
Inventors
- Patrick Shannon Pendergrast (Cambridge, MA, US)
- Robert Scott Pendergrast (Chatham, NJ, US)
- John Stephen Pendergrast (Stockholm, NJ, US)
- Anna Irmina Markowska (Brookline, MA, US)
Cpc classification
C12N15/1003
CHEMISTRY; METALLURGY
C12N15/1006
CHEMISTRY; METALLURGY
B01D2009/009
PERFORMING OPERATIONS; TRANSPORTING
C07H21/00
CHEMISTRY; METALLURGY
C07K1/36
CHEMISTRY; METALLURGY
B01D2009/0086
PERFORMING OPERATIONS; TRANSPORTING
Y02P20/582
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
International classification
C07H21/00
CHEMISTRY; METALLURGY
B01D21/26
PERFORMING OPERATIONS; TRANSPORTING
C12N15/10
CHEMISTRY; METALLURGY
Abstract
Compositions and methods for the isolation of protein-nucleic acid complexes, extracellular vesicle (EV) (e.g., microvesicles) and free nucleic acids (collectively referred to as bioparticles) released by mammalian cells into body fluids or cell culture media are provided. Isolated bioparticles of the current disclosure contain biomolecules that are useful as diagnostic/prognostic biomarkers or for identification of therapeutic targets (e.g., disease or disorder-associated miRNAs, circulating tumor DNA). Isolation of biomolecules results in purification and concentration. Methods for producing biofluids without detectable bioparticles, largely depleted of bioparticles, and/or possessing a reduced concentration of bioparticles compared to a biofluid starting material (collectively termed bioparticle-depleted) are provided. Bioparticle-depleted biofluid is useful, e.g., in experimental systems where desirable to obtain a biofluid lacking or substantially depleted of endogenous bioparticles from the source material. Non-toxic bioparticle absorbing materials (e.g., exosome-reducing materials) can also be used for prophylactic, therapeutic, validation and/or experimental purposes.
Claims
1. A method for isolating, amplifying or both isolating and amplifying cell-free nucleic acids from a liquid sample with enhanced efficiency comprising: a) obtaining a liquid sample from a subject or cell culture; b) contacting said liquid sample with a crystallizing agent under conditions suitable to allow for crystal formation, thereby creating an admixture; c) incubating said admixture for a period of time sufficient to allow for crystal formation; d) separating said admixture to obtain a particle fraction containing bioparticles; and e) isolating amplifying or both isolating and amplifying cell-free nucleic acids from the particle fraction containing bioparticles, thereby isolating, amplifying or both isolating and amplifying cell-free nucleic acids from the liquid sample with enhanced efficiency.
2. The method of claim 1, wherein the cell-free nucleic acids comprise cell-free DNA (cfDNA), optionally circulating tumor DNA (ctDNA).
3. The method of claim 1, wherein the cell-free nucleic acids comprise cell-free RNA.
4. The method of claim 1, wherein the crystallizing agent is selected from the group consisting of monosodium urate, uric acid, a salt thereof and a combination thereof.
5. The method of claim 1, wherein said admixture is present in an array of admixtures, optionally wherein said array is a 96 well array.
6. (canceled)
7. The method of claim 1, wherein said admixture volume is less than about 1 ml.
8. The method of claim 1, wherein said step (d) of separating comprises centrifugation, optionally wherein said centrifugation creates a pellet that is resuspended in a solution, optionally wherein said pellet is resuspended in a volume of solution that is less than the starting volume of the liquid sample, optionally wherein said resuspended pellet solution is enriched for at least one marker known to correlate with exosomes, optionally wherein said at least one marker is selected from the group consisting of a protein marker and a nucleic acid marker.
9. (canceled)
10. The method of claim 1, wherein said period of time of step (c) is selected from the group consisting of at least 1 minute, at least 5 minutes, at least 10 minutes, 1-5 minutes, 5-10 minutes, 10-15 minutes, 15-30 minutes, 30 minutes or less, 15 minutes or less, 10 minutes or less and 5 minutes or less.
11. The method of claim 1, wherein said isolated bioparticles comprise microvesicles, optionally wherein said microvesicles comprise exosomes.
12. (canceled)
13. The method of claim 1, wherein the liquid sample comprises a biofluid.
14. The method of claim 1, wherein the liquid sample comprises a fluid selected from the group consisting of whole blood, blood serum, blood plasma, urine, saliva, sputum, breast milk, ascites fluid, synovial fluid, amniotic fluid, semen, cerebrospinal fluid, follicular fluid and tears.
15. The method of claim 1, wherein said isolated microvesicles comprise a population of microvesicles possessing an average diameter of between about 40 nm and about 150 nm.
16-18. (canceled)
19. The method of claim 1, wherein said crystallizing agent is monosodium urate.
20. The method of claim 1, wherein said crystallizing agent is uric acid or a salt of uric acid.
21. (canceled)
22. The method of claim 1, wherein said centrifugation is a low-speed centrifugation.
23. The method of claim 1, wherein said centrifugation is at about 2,000g.
24. A method selected from the group consisting of: A method for isolating bioparticles from a biofluid comprising: a) contacting a biofluid with a first porous bead composition for an initial period of time; b) removing the first porous bead composition from contact with the biofluid, thereby forming a bead fraction and a supernatant or eluate; c) contacting the supernatant or eluate for a second period of time with one or more compositions selected from the group consisting of: (i) a second porous bead composition; and (ii) a crystallizing agent; thereby creating an admixture; d) separating the admixture to obtain a particle containing bioparticles and/or separating the bead fraction from the biofluid and obtaining sequestered bioparticles from the bead fraction, thereby isolating bioparticles from the biofluid; A method for isolating bioparticles from a biofluid comprising: a) contacting a biofluid with a porous bead composition for an initial period of time; b) removing the porous bead composition from contact with the biofluid; and c) subjecting the biofluid to ultracentrifuge separation under conditions sufficient o allow for bioparticle isolation, thereby isolating bioparticles from the biofluid; and A method for isolating bioparticles from a biofluid comprising: a) contacting the biofluid for a period of time with both: (i) a porous bead composition; and (ii) a crystallizing agent; thereby creating an admixture; b) separating the admixture to obtain a particle containing bioparticles and porous beads; and c) obtaining bioparticles from the particle, thereby isolating bioparticles from the biofluid; A method for reducing the level of a bioparticle in a biofluid of an organism, the method comprising: contacting the biofluid of the organism with a composition for contacting a bioparticle-containing biofluid of an organism comprising a container or device containing porous beads possessing a pore size capable of sequestering the bioparticle of the biofluid upon contact with the bioparticle-containing biofluid for a time sufficient to reduce the level of the bioparticle in the biofluid of the organism, thereby reducing the level of the bioparticle in the biofluid of the organism; A method for sequestering and detecting a released bioparticle from cell culture media in vitro, comprising: i) applying porous beads to the cell culture media; ii) incubating the bead-containing media with cells under conditions appropriate for sequestration of the released bioparticle in the porous beads; iii) isolating the porous beads; and iv) detecting bioparticles sequestered by said porous beads, thereby sequestering and detecting the released bioparticle from cell culture media in vitro; A method for treating or preventing cancer in an organ of a subject having or at risk of developing cancer comprising: contacting a biofluid of the subject with a composition for contacting a bioparticle-containing biofluid of an organism comprising a container or device containing porous beads possessing a pore size capable of sequestering the bioparticle of the biofluid upon contact with the bioparticle-containing biofluid for a time sufficient to reduce the level of the bioparticle in the biofluid of the subject. thereby treating or preventing cancer in the organ of the subject having or at risk of developing cancer; A method for sequestering released bioparticles in the saliva of a subject, comprising: i) contacting a container or device containing porous beads contained within a porous membrane and/or porous cellulose with the mouth of the subject under conditions that allow for sequestration of saliva bioparticles; ii) removing the container or device from the mouth of the subject: iii) removing the porous beads from the container or device; iv) releasing bioparticles from the porous beads, optionally by contacting the porous beads with a chaotropic agent or a detergent; and v) assaying the released bioparticles, optionally using one or more methods selected from the group consisting of SDS PAGE/immunoblot, PCR and mass spectrometry; and A method for disrupting bioparticle-mediated signaling in a biofluid of an organism, the method comprising: contacting the biofluid of the organism with a porous container or device containing porous beads possessing a pore size capable of sequestering the bioparticle performing bioparticle-mediated signaling for a time sufficient to reduce the level of the bioparticle in the biofluid of the organism, thereby disrupting bioparticle-mediated signaling in the biofluid of the organism.
25. The method of claim 24, wherein: the biofluid is a liquid sample obtained from a subject or cell culture; the biofluid is present in a subject; the first and/or second porous bead composition comprises siliceous beads, optionally diatomaceous earth (DE) and/or perlite; the biofluid is selected from the group consisting of whole blood, blood serum, blood plasma, urine, saliva, sputum, breast milk, ascites fluid, synovial fluid, amniotic fluid, semen, cerebrospinal fluid, follicular fluid and tears, optionally wherein the biofluid is urine, saliva or blood; the first porous bead composition is present in a column or matrix structure; the initial period of time is less than a minute; the second period of time is longer than 5 minutes, optionally 15 minutes to 30 minutes, or more, optionally the second period of time is selected from the group consisting of at least 1 minute, at least 5 minutes, at least 10 minutes, 1-5 minutes, 5-10 minutes, 10-15 minutes, 15-30 minutes, 30 minutes or less, 15 minutes or less, 10 minutes or less and 5 minutes or less; both a second porous bead composition and a crystallizing agent contact supernatant or eluate in step (c); the crystallizing agent is selected from the group consisting of monosodium urate, uric acid, a salt thereof and a combination thereof; step (b) comprises low-speed centrifugation, optionally at about 2,000g; said admixture is present in an array of admixtures, optionally wherein said array is a 96 well array; said admixture volume is less than about 1 ml; said step (d) of separating comprises centrifugation; the isolated bioparticles comprise microvesicles, optionally the isolated microvesicles comprise a population of microvesicles possessing an average diameter of between about 40 nm and about 150 nm, optionally the isolated bioparticles comprise exosomes; the pore size of the porous beads is about 0.1 to 10 microns, optionally about 0.2 to 5 microns, optionally about 0.5 to 2 microns, optionally about 1 micron; the isolated bioparticles comprise a biomarker selected from the group consisting of bladder cancer biomarkers B1 integrin protein, A6 integrin protein, CD73 protein, Trop 1 protein, EDIL-3 protein, Mucin4 protein, GALANT1 mRNA and/or LASS2; prostate cancer biomarkers PCA3 mRNA, ERG mRNA, TMPRSS2:ERG RNA/DNA and/or ITGA3 protein/RNA; diabetes biomarker AQ2 protein; lupus biomarker mir-335 miRNA and/or mir-302d miRNA, kidney damage biomarker cystatinC mRNA, and glomerular disease biomarker nephrin protein, TRPC6 protein, INF2 protein and/or phospholipase A2R protein, optionally further comprising identifying one or more of said biomarkers in the isolated bioparticles; the bioparticle of the biofluid is an exosome, optionally wherein reduction of the level of exosomes in the biofluid is confirmed by determining whether or not sequestered material is enriched for protein and/or nucleic acid makers that are known to preferentially segregate with exosomes: reduction in protein and/or nucleic acid markers of the bioparticle within the biofluid after contact with the composition, relative to an appropriate control, indicates sequestration or reduction of the bioparticles in the biofluid; the bioparticle of the biofluid is a protein-nucleic acid complex, optionally an AGO2-miRNA particle, optionally wherein reduction of the level of the AGO2-miRNA particle in the biofluid is confirmed by assaying for specific miRNAs known to take part in an AGO2-miRNA particle or by assaying for AGO2 protein; the bioparticle of the biofluid is a cell-free nucleic acid particle; further comprising v) assaying the cells to determine an effect of the applied porous beads; the porous beads are non-toxic, optionally wherein the porous beads are siliceous beads, optionally diatomaceous earth (DE); isolating step iii) comprises low speed centrifugation; the bioparticle is sequestered into a container or device, optionally a pouch, which is optionally placed in the vicinity of the bioparticle-generating cells; the container or device contains a porous bead resin surrounded by a porous membrane and/or porous cellulose or housing that allows bioparticles to flow into the container or device to be captured but optionally does not allow for direct contact between the resin and cells; the composition is placed in the proximity of a tumor or a site susceptible to formation of a tumor, optionally for a duration of time selected from the group consisting of 10 minutes to 30 minutes, 15 minutes to an hour, 30 minutes to 2 hours, 1-3 hours, 2-4 hours, 3-10 hours, 5-24 hours, 1-2 days, 2-4 days, 3 days to a week, one to three weeks, 2-4 weeks, 2 weeks to 2 months, one month to four months, two months to six months, three months to a year, and six months to two years or more; the cancer is a bladder cancer; the composition comprises siliceous beads optionally DE, optionally within a device or container, optionally a device or container bound by a porous membrane and/or porous cellulose, optionally wherein the device or container is placed within the bladder of a subject, optionally in proximity of a bladder cancer tumor and/or in proximity to a site susceptible to bladder cancer formation; and/or the composition is placed within the bladder of a subject, optionally in proximity of a bladder cancer tumor and/or in proximity to a site susceptible to bladder cancer formation, optionally for a length of time selected from the group consisting of 10 minutes to 30 minutes, 15 minutes to an hour, 30 minutes to 2 hours, 1-3 hours, 2-4 hours, 3-10 hours, 5-24 hours, 1-2 days, 2-4 days, 3 days to a week, one to three weeks, 2-4 weeks, 2 weeks to 2 months, one month to four months, two months to six months, three months to a year, and six months to two years or more.
26-44. (canceled)
45. A composition selected from the group consisting of: A kit for isolating bioparticles from a biofluid comprising a porous bead composition for pretreatment of the biofluid, and instructions for its use; and A composition for contacting a bioparticle-containing biofluid of an organism comprising: a container or device containing porous beads possessing a pore size capable of sequestering the bioparticle of the biofluid upon contact with the bioparticle-containing biofluid.
46. (canceled)
47. The composition of claim 45, wherein: the bioparticle of the biofluid is an exosome; the bioparticle of the biofluid is a protein-nucleic acid complex, optionally an AGO2-miRNA particle; the bioparticle of the biofluid promotes a disease or disorder, optionally wherein the disease or disorder is cancer, optionally wherein the cancer is a bladder or an oral cancer; the container or device is a pouch optionally a pouch possessing a porous membrane and/or porous cellulose as an outer layer, optionally a porous cellulose bag; the porous beads are non-toxic, optionally wherein the porous beads are siliceous beads, optionally diatomaceous earth (DE).
48-72. (canceled)
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF THE INVENTION
[0215] Certain aspects of the current disclosure provide compositions and methods for producing preparations of isolated secreted microvesicles, RNA, DNA and protein-nucleic acid complexes (collectively called bioparticles) from a liquid sample. The current disclosure additionally provides methods for producing biofluids and blood serum/plasma that has been at least partially depleted of bioparticles.
[0216] The current disclosure also provides improved compositions and methods for producing preparations of isolated secreted microvesicles, RNA, DNA and protein-nucleic acid complexes (collectively called bioparticles) from a liquid sample. The current disclosure also provides improved methods for producing biofluids and blood serum/plasma that has been at least partially depleted of bioparticles.
[0217] In addition, the current disclosure provides compositions and methods for sequestering and/or reducing bioparticles (including, e.g., secreted microvesicles and/or extracellular vesicles (EVs), RNA, DNA and protein-nucleic acid complexes) by contacting a biofluid with a composition that includes porous beads.
[0218] These methods have a number of advantages over the state of the art, which will be apparent from the discussion herein.
[0219] In certain aspects, the current disclosure provides methods for the isolation of bioparticles (including, e.g., microvesicles, exosomes, etc.) from a liquid sample (e.g., a biofluid of a subject or cell culture), optionally by a method that involves contacting the biofluid with porous beads (e.g., DE, perlite, etc.), optionally for a brief period of time before ending such contact, and then contacting this pre-cleared biofluid sample with one or more of the following compositions, for improved isolation of bioparticles from the biofluid sample (or removal from/reduction of such bioparticles within the biofluid sample so treated): (1) contacting the biofluid (the pre-cleared biofluid) with porous beads (e.g., DE), optionally for longer duration than the initial pre-clearing contacting; (2) contacting of the biofluid (the pre-cleared biofluid) with both porous beads (e.g., DE) and a crystallization/precipitation reagent such as Na Urate (combination method), optionally for a longer duration than the initial pre-clearing contacting; (3) contacting of the biofluid (the pre-cleared biofluid) with a crystallization/precipitation reagent such as Na Urate, optionally for a longer duration than the initial pre-clearing contacting; or (4) while more onerous, traditional bioparticle/EV isolation methods, such as ultracentrifugation, can also be performed upon such pre-cleared samples. Kits for performance of such of such isolation steps, including such improved isolation/bioparticle sequestration/reduction steps, and instructions for their use, are also provided.
[0220] In some aspects, the current disclosure specifically provides therapeutic methods for the sequestration and/or reduction of bioparticles upon contacting porous beads with a biofluid of an organism or subject. In certain embodiments, implantable, porous pouches and/or devices containing porous beads (e.g., diatomaceous earth and/or perlite) are contacted with a biofluid of a subject, e.g., via implantation within a bladder or other organ of a subject, thereby disrupting bioparticle and/or exosome-mediated signaling, to therapeutic end, optionally allowing for isolation of such bioparticles from the implantable composition/device. In other embodiments, a composition of the current disclosure is contacted with a mucous membrane of a subject, thereby causing sequestration and/or reduction of bioparticles within contacted mucus and/or saliva of the subject, optionally with therapeutic effect.
[0221] Specific diseases or disorders contemplated for treatment using the compositions of the current disclosure include hyperproliferative diseases (e.g., cancer), although the methods and compositions of the current disclosure can be applied to any disease or disorder that is modulated (e.g., upregulated) via bioparticle signaling. Kits, devices and/or pouches used to contact a subject with porous beads of the current disclosure, as well as instructions for their use, are also provided.
Extracellular Vesicles and Bioparticles
[0222] A diverse collection of proteins, nucleic acids, protein-nucleic acid complexes, and membrane-bound structures are released from cells, particularly mammalian cells, during the course of their life and death (
[0223] Exemplary nucleic acids that are useful in diagnostics include both DNA (also called cell-free DNA (cfDNA), circulating tumor DNA (ctDNA) and/or circulating DNA) and RNA (including cell-free RNA). Cell-free DNA can be found associated with extra-cellular vesicles (EVs) and also completely free of vesicles, although it may be bound by protein. Cell-free DNA (cfDNA) released from necrotic tumor cells (also known as circulating tumor cell DNA (ctDNA)) has been used to ascertain the existence, type and genotype of the tumor cell. Cell-free RNA (cfRNA) also can be found associated with EVs (such as exosomes, sometimes called exo-RNA) or free of vesicles as part of protein-nucleic acid complexes including, e.g., Ago2-microRNA complexes, which are known to exist as stable complexes in cell-free biofluids (Arroyo et al. PNAS 108: 5003-5008). Such complexes are released into the fluids of a subject (e.g., urine, blood, saliva, etc.) according to the status of the cell and/or upon degradation of the cell after death.
[0224] Exemplary protein-nucleic acid complexes include protein-microRNA complexes, which are also known to exist as stable complexes in cell-free biofluids (Arroyo et al.).
[0225] Ago2-microRNA complexes, cfDNA and cfRNA are released into the fluids of a subject (e.g., urine, blood, etc.) according to the status of the cell and/or upon degradation of the cell after death.
[0226] Membrane-bound structures (also known as extracellular vesicles or EVs, or microvesicles) released from or otherwise derived from cells include exosomes, microvesicles, apoptotic bodies, and high density lipoprotein (HDL)-particles. (It is noted that the terms extracellular vesicles (EVs) and microvesicles are used interchangeably herein to describe all cell-derived membrane-bound structures. It is further noted that, as would be evident to the skilled artisan, compositions and methods of the current disclosure recited as directed to, e.g., exosome sequestration/reduction/isolation, can also be applied to sequestration/reduction/isolation of other cell-derived membrane bound structures, e.g., extracellular vesicles, microvesicles, etc.)
[0227] Methods and compositions for the rapid and inexpensive isolation of extracellular membrane particles, including microvesicles, exosomes, and apoptotic bodies, as well as any accompanying biomarkers, from biofluids such as urine and saliva, have recently been identified (see PCT/US2015/043768). Such methods have been demonstrated as useful for isolating membrane-free protein-nucleic acid particles, messenger RNA, and DNA as well. The methods allow for obtaining intact bioparticles for use in mechanistic, vaccine-related, delivery-related and therapeutic studies.
[0228] Such methods use common laboratory reagents and apparatus, and do not require high-speed centrifugation, such as ultracentrifugation. In addition, these methods provide higher yields than more traditional methods (e.g., ultracentrifugation), allowing for the isolation of important biomarkers and/or therapeutic targets from a smaller volume of sample than such traditional methods allow. The recently developed methods also allow for generation of cell culture media that are free of endogenous bioparticles, or have reduced concentrations of endogenous bioparticles compared to traditional complete media.
[0229] One of the significant technical challenges in current research in cell-free bioparticles is the problem of how to efficiently isolate the bioparticles from various sources. Current methodologies to isolate secreted bioparticles are constrained by technical limitations and other drawbacks. These known methodologies are labor intensive, time-consuming, costly, and can be unreliable for different fluids; see Tauro et al., Comparison of ultracentrifugation, density gradient separation, and immunoaffinity capture methods for isolating human colon cancer cell line L1M1863-derived exosomes, Methods 56(2): 293-304 (print February 2012, Epub Jan. 21, 2012), doi:10.1016/j.ymeth.2012.01.002.
Extracellular Vesicle (EV) Function
[0230] The function of EVs is not clearly understood, although in certain capacities, they are believed to act as nano-shuttles for the transport and delivery of information from one location and/or cell type to distant locations and/or other cell types (Mathivanan and Simpson, J. Proteomics 73101:1907-1920 (2010)). Also, they are theorized to be involved in a wide variety of physiological processes, including cardiac disease, adaptive immune responses to pathogens, and in tumor biology. It has been suggested that microvesicles might function in tumor immune suppression, metastasis, and tumor-stroma interactions. Microvesicles are particularly thought to play a role in immune system cellular communication, for example, involving dendritic cells and B cells (Raposo et al., J. Exp. Med. 183: 1161 (1996)). Importantly, there is recent evidence that EVs released from tumor cells (also known as Tumor Derived Exosomes or TEXs) can promote tumor invasiveness and/or metastasis (Suchorska and Lach, Oncol. Rep. (2015) PMID: 26707854), For instance, exosomes released from bladder cancer cells can promote epithelial-to-mesenchymal transition in urothelial cells, setting the stage for bladder cancer invasiveness (Franzen et Oncogenesis 4: e163 (2015)).
[0231] One of the significant technical challenges in current microvesicle research relates to the problem of how to isolate microvesicles efficiently from their various sources. Current methodologies for isolating secreted microvesicles, including but not limited to exosomes, are constrained by technical limitations and other drawbacks, These known methodologies are labor intensive, time-consuming, costly, and can be unreliable for different fluids; see Tauro et al., Comparison of ultracentrifugation, density gradient separation, and immunoaffinity capture methods for isolating human colon cancer cell line LIM1863-c rived exosomes. Methods 56(2):293-304).
[0232] In particular, investigators and clinicians have previously possessed few choices for the selective, non-toxic knock-out, elimination and/or amelioration of EVs in vitro (i.e., in cell culture) or in vivo (i.e., in animal models or human subjects in clinical trials). Such methods would enable pre-clinical validation of exosomal targets, discovery of disease biomarkers and possibly even provide for clinical therapeutic intervention of disease-altering exosomal effects. One previously available method for EV reduction has been to use antibodies specific for membrane proteins to sequester EVs. However, since many cells possess membrane proteins identical to those of EVs, it has been impossible to prevent such antibodies from affecting cells as well as exosomes. Furthermore, antibodies are expensive and possess limited capacity. A second available alternative has been to use Heparin to bind EVs (Franzen et al., Oncogenesis. 4: e163 (2015)). However, Heparin has a very limited half-life and would thus require constant dosing to maintain any manner of blockade/chronic depletion of EVs. Furthermore, Heparin is well known to affect cells and has been shown to possess significant side effects when used therapeutically in humans and animals (Smythe et al. Guidance for the practical management of the heparin anticoagulants in the treatment of venous thromboembolism. J. Thromb. Thrombolysis. 41: 165 (2016); Gurbuz et al. Heparin toxicity in cell culture: a critical link in translation of basic science to clinical practice. Blood Coagul. Fibrinolysis. 24: 742 (2013)).
Microvesicles
[0233] The term microvesicles (also known as microparticles) refers to a heterogeneous in vivo collection of membrane bound (i.e., encapsulated) biological structures. These structures are formed from lipid bilayer, which is the same lipid bilayer that comprises eukaryotic cell membranes. Microvesicles can reside within the cell, or in the extracellular environment. Microvesicle structures (intracellular and/or extracellular) are produced by nearly all mammalian cell types, as well as during in vitro cell culture.
[0234] The molecular composition of microvesicles is diverse, containing and/or transporting a variety of nucleic acids, proteins and lipids. Microvesicle molecular composition is generally reflective of the plasma membrane and antigenic content of the cell types, tissues and organs from which they originate. Mathivanan and Simpson, Exosomes: extracellular organelles important in intercellular communication, J. Proteomics 73(10):1907-19:20 (2010). Although protein composition of the microvesicles varies, most of these structures are enriched for various soluble protein markers, including HSP70, Hsc70, CD63, CD9, CD81 and others. Circulating microvesicles have also been reported to contain nucleic acids, including messenger RNAs, DNAs, and relatively high levels of small RNAs and microRNAs.
[0235] Circulating microvesicles are associated with numerous cell functions, including intercellular (cell-to-cell) communication, removal of metabolic byproducts and toxins (including misfolded proteins, cytotoxic agents and metabolic waste), angiogenesis, tissue regeneration, endocytic recycling of the plasma membrane, selective removal of plasma membrane proteins and regulation of immune functions such as antigen presentation. Some microvesicles have been shown to transport messenger RNA (mRNA) and microRNA (miRNA), which is highly suggestive of microvesicles functioning as messengers that allow one cell type to regulate the activity of a distant cell type by acting as a shuttle that can merge with the distant cell and release its contents into that target recipient cell. This microvesicle shuttle can utilize the body fluids to travel to distant sites and control the activity of distant target cells.
[0236] Circulating microvesicles (cMVs), or synonymously, extracellular microvesicles (eMVs) or extracellular vesicles (EVs), describe an eclectic group of microvesicles that are released by cells, and therefore, exist in extracellular spaces and/or reside in body fluids. The mammalian body fluids that are known or suspected to contain cMVs include, but are not limited to, blood, urine, saliva, breast milk, tears, sweat, ascites fluid and cerebrospinal fluid. Secreted microvesicles are also found in cell culture media that has been exposed to cultured mammalian cells.
[0237] With regard to defining and categorizing the cMV molecules that can be found in body fluids, there is lack of consensus as to the nomenclature and description of the different types of cMV particles. Some literature distinguishes at least three subcategories of circulating microvesicles, based on their mechanistic origin. The molecular/cellular mechanisms that produce microvesicles are theorized to include (i) exocytosis of intracellular multivesicular bodies, (ii) outward budding, fission and shedding of plasma membrane, and (iii) byproducts of apoptosis. Time diverse collection of circulating microvesicle structures can range in size from about 20 nanometers (nm) to upwards of about 1,000 nm (i.e., 1.0 micrometer, micron, or .Math.) in diameter.
[0238] The first recognized subgroup of cMVs are those produced by direct plasma membrane budding, fission and shedding. Some sources describe these shed microvesicles as generally large, namely with lower sizes limits of at least 100 nm or 200 nm, and with an upper size limit of about 1,000 nm in diameter. Some have proposed that these structures be termed ectosomes or shedding microvesicles (SMVs). Still other groups state that ectosome particles may be as small as 40 or 50 nm in diameter.
[0239] A second recognized subgroup of cMVs are exosomes, that is, the preformed microvesicles that are released from the cell following the exocytic fusion of intracellular multivesicular bodies with the plasma membrane. These exosome structures are generally smaller than ectosomes, and have an upper size limit estimated to be about 100, 150 or 200 nm, and a lower size limit of about 40 nm or 50 nm. However, various sources differ in their size-based definitions for exosomes and this size distinction remains unresolved.
[0240] A third group of structures is the apoptotic blebs released by dying cells. These membrane structures have a less well-defined size range, and may be anywhere from about 50 nm to about 5,000 nm in diameter.
[0241] A unified microvesicle nomenclature and classification system utilizing broadly accepted definitions has been elusive in the field. In the literature, microvesicles have been alternatively referred to as microparticles, nanoparticles, exosomes, ectosomes, epididimosomes, argosomes, exosome-like vesicles, promininosomes, prostasomes, dexosomes, texosomes, archeosomes, oncosomes, exosome-like vesicles, apoptotic blebs, extracellular vesicles and shedding microvesicles. In some publications, uses of these terms is conflicting or overlapping. Simpson and Mathivanan (2012), Extracellular Microvesicles: The Need for Internationally Recognized Nomenclature and Stringent Purification Criteria. J Proteomics Bioinform (2). doi:10.41.72/jpb.10000e10. One source suggests that a preferred nomenclature for circulating microvesicle is based on the microvesicle's mechanism of origin. Namely, these categories would be (i) the ectosomes produced by membrane budding, (ii) the exosomes produced by the exocytosis to intracellular multivesicular bodies, and (iii) the membrane blebs produced by the process of apoptosis.
[0242] The release of exosomes was highlighted from different cell types in a variety of physiological contexts. Thus, it has been shown that B cells release exosomes bearing molecules of the major histocompatibility complex class II, which play a role in antigen presentation (Raposo et al., J. Exp. Med. 183 (1996) 1161). Similarly, it has been shown that dendritic cells produce exosomes (also referred dexosomes) with specific structural and functional characteristics, and playing a role in mediating the immune response, including the stimulation of cytotoxic T lymphocytes (Zitvogel et al., Nature Medicine 4 (1998) 594). It has also been shown that tumor cells secrete in a controlled manner, specific exosomes (also designated texosomes) bearing tumor antigens and are able to present these antigens or to transmit them to antigen-presenting cells. It is also known that mast cells accumulate molecules in intracellular vesicular compartments, which can be secreted in response to signals (Smith and Weis, Immunology Today 17 (1996) 60). In general, it seems that the cells emit signals and communicate with each other through membrane vesicles they release, which may carry antigenic patterns, MHC molecules, or any other signal (cytokine, growth factor, etc.) which have special structural and functional characteristics and are produced in different physiological situations.
[0243] Membrane-bound structures (also known as extracellular vesicles or microvesicles) released from or otherwise derived from cells include exosomes, microvesicles, apoptotic bodies, and high density lipoprotein (HDL)-particles. (It is noted that the terms extracellular vesicles and microvesicles are used interchangeably herein to describe all cell-derived membrane-bound structures.)
[0244] The function of extracellular vesicles is not clearly understood, although they are theorized to act as nano-shuttles for the transport and delivery of information from one location and/or cell type to distant locations and/or other cell types (Mathivanan and Simpson, Exosomes: extracellular organelles important in intercellular communication, J. Proteomics 73(10): 1907-1920 (2010)). Also, they are theorized to be involved in a wide variety of physiological processes, including cardiac disease, adaptive immune responses to pathogens, and in tumor biology. It has been suggested that microvesicles function in tumor immune suppression, metastasis, and tumor-stroma interactions. In particular, microvesicles are believed to function in immune system cellular communication, for example, signaling involving dendritic cells and B cells (Raposo et al., J. Exp. Med. 183: 1161 (1996)).
[0245] The ubiquitous presence of circulating microvesicles in body fluids, their association with a broad range of physiological processes, as well as their elevated levels in human disease, suggest that microvesicles could serve as tools in molecular medicine, as measures of physiological state, disease diagnostics, and possibly therapeutic targeting.
[0246] Although the study of microvesicles/exosomes had been greatly advanced with the development of analytical systems such as nanoparticle tracking analysis (NTA) and fluorescent nanoparticle tracking analysis (FNTA; see (i) Van der Pol et al., Optical and non-optical methods for detection and characterization of microparticles and exosomes, Journal of Thrombosis and Haemostasis (2010), doi: 10.1111/i.1538-7836.2010.04074.x: and (ii) Dragovic et al., Sizing and phenotyping of cellular vesicles using Nanoparticle Tracking Analysis, Nonomedicine: Nanotechnology, Biology and Medicine (2011), doi:10.1016/j.nano.2011.04.003), other technical challenges remain related to isolation and use of microvesicles/exosomes.
Methods for Isolating Bio Particles
[0247] In certain aspects, the current disclosure provides methods for the isolation of bioparticles, specifically including isolation of cell-free DNA, including circulating tumor DNA (ctDNA) from liquid samples. In certain embodiments, the liquid sample is urine. From urine as an example, certain methods of the current disclosure comprise the following steps:
[0248] A) (Optional) Preparing a Whole Urine Prespin Treatment Solution (also called Solution 1)
[0249] The purpose of the Whole Urine Prespin Treatment Solution is to reduce the amount of bioparticles lost in the first spin (prespin), which is typically performed to reduce the amount of cells and debris in the Whole Urine sample.
[0250] It is well known in the field that spinning urine at speeds above 17,000g can lead to the loss of microvesicles due to the trapping action of the protein THP (also called uromodulin). However, it was discovered that a large amount of microvesicles could also be lost in the lower speed spins (below even 3000g) that are typically used to remove cells and debris (see
[0251] In certain embodiments, the Whole Urine Prespin Treatment Solution consists of the reducing agent TCEP. TCEP is preferred over DTT for this purpose, as it is active in a broader range of pH. In one embodiment, the concentration of the TCEP in the 10 solution would be at a concentration of 160 mM. Other embodiments have the TCEP 10 concentration being between 80 mM and 300 mM. Other embodiments use other reducing agents such as DTT at similar concentrations.
[0252] In other embodiments, the Whole Urine Prespin Treatment Solution consists of an acid buffer plus reducing agent such that addition of the acid buffer-containing Whole Urine Prespin Treatment Solution reduces the pH of the Whole Urine below 6.
[0253] In other embodiments where the reducing agent is not used, the Whole Urine Prespin Treatment Solution consists of a basic buffer that increases the pH of the Whole Urine to above 7 as it was discovered that without reducing agent present, less bioparticles are lost if the pH of the sample is above 7.
[0254] B) (Optional) Adding the Whole Urine Prespin Treatment Solution to the whole urine sample.
[0255] In certain embodiments, a 1/10.sup.th volume of a 10 Whole Urine Prespin Treatment Solution is added to the whole urine sample to create a mixture. In other embodiments any combination of Prespin Treatment Solution and Urine Sample yielding a mixture with a final concentration of the TCEP or other reducing agent of from 5 mM to 30 mM and a pH below 6 is acceptable or, if no reducing agent is used, a pH above 7. No incubation is necessary; the next step can be taken immediately.
[0256] C) Centrifuging the Mixture
[0257] The mixture is subjected to a centrifugation. The centrifugation typically forms a pellet and a supernatant, although pelleted material may not be visible to the eye. In contrast to the prior art, this centrifugation does not require ultracentrifugation, e.g., does not require centrifugal forces in excess of 100,000g. This centrifugation can be done at slower speeds, for example, to generate RCF values of not more than 30,000g, or not more than 20,000g, or not more than 12,000g, or not more than 10,000g, or not more than 5,000g, or not more than 2,000g, or not more than 1,500g. In one embodiment, a centrifugation producing 1,000g is used. The length of time for centrifugation is not limiting. In one embodiment, the centrifugation is for 5 minutes. Alternatively, the centrifugation can proceed for one or more minutes, two or more minutes, three or more minutes, four or more minutes, six or more minutes, seven or more minutes, eight or more minutes, nine or more minutes, ten or more minutes, fifteen or more minutes, twenty or more minutes, etc.
[0258] D) Removing the Supernatant
[0259] Following the spin, the resulting supernatant is carefully removed so as not to disturb the pellet, and the pellet is discarded.
[0260] E) Combining the Urine Supenatant from D) with the Crystallization/Precipitation Solution (also called solution 2)
[0261] To initiate the crystallization/precipitation of bioparticles, Solution (see below) is added to the Supernatant generated in step D) to create a mixture. In one embodiment, a 1/10.sup.th volume of a 10 concentration of Solution 2 is added to the supernatant, however, any combination that yields a 0.5 to 5 final concentration of Solution 2 in the mixture is acceptable.
[0262] F) Incubating the Resulting Mixture
[0263] The resulting mixture is then incubated. The incubation can be with any degree of cooling, for example at 5 C., although such cooling is not always required. The incubation times can vary, and are not in any way limiting. For example, incubation can be anywhere between 0 minutes to overnight (e.g., 16 hours). The incubation can be with or without mixing, and the mixing during the incubation period can be constant or intermittent. In certain embodiments a 15-minute incubation on ice is performed.
[0264] G) Centrifuging the Mixture
[0265] The mixture from F) is subjected to a centrifugation. The centrifugation typically forms a pellet and a supernatant, although pelleted material may not be visible to the eye. In contrast to the prior art, this centrifugation does not require ultracentrifugation, e.g., does not require centrifugal forces in excess of 100,000g. This centrifugation can be done at slower speeds, for example, to generate RCF values of not more than 30,000g, or not more than 20,000g, or not more than 12,000g, or not more than 10,000g, or not more than 5,000g, or not more than 2,000g, or not more than 1,500g. In the one embodiment, a centrifugation producing 2,000g is performed. The length of time for centrifugation is not limiting. In one embodiment, the centrifugation is for 5 minutes.
[0266] H) Removing the Supernatant
[0267] Following the spin, the resulting supernatant is carefully removed so not o disturb the pellet, and this supernatant is discarded.
[0268] I) Resuspending the Pelleted Material
[0269] After removal of the supernatant, the pellet is resuspended in any desired resuspension solution and collected for further analysis. The resuspension solution can use either water, phosphate buffered saline (PBS), or any other suitable aqueous, such as any isotonic solution. In some embodiments, the resuspension solution is basic in nature, for example, 100 mM Tris pH 8. The volume used for the resuspension is most typically the smallest possible practical volume, and is typically many times smaller than the volume of the original liquid sample comprising the secreted microvesicles. In some embodiments, the volume of the resuspension solution is smaller by at least one order of magnitude than the volume of the original liquid sample.
Traditional Isolation of Microvesicles and Bioparticles
[0270] One of the significant technical challenges in current microvesicle research relates to how to efficiently isolate the microvesicles from various sources. Current methodologies to isolate secreted microvesicles (including but not limited to exosomes) are constrained by technical limitations and other drawbacks. These known methodologies are labor intensive, time-consuming, costly, and can be unreliable for different fluids; see Tauro et al., Comparison of ultracentrifugation, density gradient separation, and immunoaffinity capture methods for isolating human colon cancer cell line LIM1863-derived exosomes, Methods 56(2): 293-304 (print Feb 2012, Epub Jan 21, 2012), doi:10.1016/j.ymeth.2012.01.002.
[0271] Ultracentrifugation is the traditional method for microvesicle isolation. Generally, centrifugation refers to the process where a centrifugal force is applied to a mixture, whereby more-dense components of the mixture migrate away from the axis of the centrifuge relative to other, less-dense components in the mixture. The force that is applied to the mixture is a function of the speed of the centrifuge rotor, and the radius of the spin. In most applications, the force of the spin will result in a precipitate (a pellet) that gathers at the bottom of the centrifuge tube, where the remaining solution is properly called a supernate or supernatant. In other similar applications, a density-based separation or gradient centrifugation technique is used to isolate a particular species from a mixture that contains components that are both more dense and less dense than the desired component (e.g., OptiPrep).
[0272] During the circular motion of a centrifuge rotor, the force that is applied is the product of the radius and the angular velocity of the spin, where the force is traditionally expressed as acceleration relative to g, the standard acceleration due to gravity at the Earth's surface. The centrifugal force that is applied is termed the relative centrifugal force (RCF), and is expressed in multiples of g (or x g).
[0273] The centrifugation procedures that have been used to isolate circulating microvesicles can incorporate as many as five centrifugation steps, with at least two of these spins requiring centrifugal forces in excess of 100,000g for several hours. Generally, ultracentrifugation is centrifugation conditions that produce forces in excess of 100,000g. These ultracentrifugation procedures are time consuming and labor intensive, and furthermore, are constrained by the requirement for expensive ultracentrifugation equipment. They can also be unreliable for certain fluids (see
[0274] Size exclusion chromatography can also be used to isolate microvesicles, for example, by using a Sephadex G200 column matrix. This approach is also time consuming and the yields are inconsistent. It also may be difficult or expensive to scale up to larger quantities of biofluid. Finally, these columns can be clogged by viscous biofluids.
[0275] Selective immunoaffinity capture (including immuno-precipitation) can also be used to isolate circulating microvesicles, for example, by using antibodies directed against the epithelial cell adhesion molecule, a type-1 transmembrane cell-surface protein (also known as EpCAM, CD326, KSA, TROP1). The anti-EpCAM antibodies can be coupled to magnetic microbeads, such as Dynabeads magnetic beads. This method has very low yields compared to other methods, and is costly due to the use of the immuno-reagents and magnetic beads, and further, these system reagents cannot be reused for subsequent isolations.
Enhanced Methods for Isolating Bioparticles
[0276] In certain aspects, the present disclosure provides enhanced methods for the isolation of bioparticles from liquid samples. In certain embodiments, the liquid sample is urine. From urine as an example, certain methods of the current disclosure comprise the following steps:
[0277] A) (Optional) Preparing a Whole Urine Prespin Treatment Solution (also called Solution 1) Performed as described above.
[0278] B) (Optional) Adding the Whole Urine Prespin Treatment Solution to the whole urine sample.
[0279] Performed as described above.
[0280] C) Optionally performed while performing the prespin treatment of (A) and/or (B) above, porous beads (e.g., DE, perlite, etc.) can also be added to the biofluid (here, urine), before performing the centrifugation of step (D) below, thereby forming pre-cleared biofluid sample under the improved methods of the current disclosure.
[0281] D) Centrifuging the Mixture
[0282] The mixture is subjected to a centrifugation. The centrifugation typically forms a pellet and a supernatant, although pelleted material may not be visible to the eye. In contrast to the prior art, this centrifugation does not require ultracentrifugation, e.g., does not require centrifugal forces in excess of 100,000g. This centrifugation can be done at slower speeds, for example, to generate RCF values of not more than 30,000g, or not more than 20,000g, or not more than 12,000g, or not more than 10,000g, or not more than 5,000g, or not more than 2,000g, or not more than 1,500g. In one embodiment, a centrifugation producing 1,000g is used. The length of time for centrifugation is not limiting. In one embodiment, the centrifugation is for 5 minutes. Alternatively, the centrifugation can proceed for one or more minutes, two or more minutes, three or more minutes, four or more minutes, six or more minutes, seven or more minutes, eight or more minutes, nine or more minutes, ten or more minutes, fifteen or more minutes, twenty or more minutes, etc.
[0283] E) Removing the Supernatant
[0284] Following the spin, the resulting supernatant is carefully moved so as not to disturb the pellet, and the pellet is discarded.
[0285] F) If the supernatant has not yet been contacted with a porous bead (to pre-clear the sample), or as an alternative to the above prespin procedure, the supernatant of the biofluid sample, or a whole biofluid sample (non-prespin) is contacted with a porous bead (e.g., DE, perlite, etc.) for a period of time as recited elsewhere herein, and this pre-clearing contacting is terminated either via low-speed centrifugation as described elsewhere herein, via elution of pre-cleared biofluid from a column or matrix formed by the porous beads, or by other method known in the art, thereby forming a pre-cleared biofluid sample/supernatant.
[0286] G) Combining the Biofluid Sample/Supernatant (e.g., Urine Supernatant) from F) with a Crystallization/Precipitation Solution (e.g., solution 2), or with a porous bead (e.g., DE, perlite, etc.), for bioparticle isolation purposes.
[0287] To initiate the crystallization/precipitation of bioparticles where a crystallization/precipitation solution is employed, Solution 2 (see below) is added to the Sample/Supernatant generated in step F) to create a mixture. In one embodiment, a 1/10.sup.th volume of a 10 concentration of Solution 2 is added to the supernatant, however, any combination that yields a 0.5 to 5 final concentration of Solution 2 in the mixture is acceptable.
[0288] H) Incubating the Resulting Mixture
[0289] The resulting mixture is then incubated. The incubation can be with any degree of cooling, for example at 5 C., although such cooling is not always required. The incubation times can vary, and are not in any way limiting. For example, incubation can be anywhere between 0 minutes to overnight (e.g., 16 hours). The incubation can be with or without mixing, and the mixing during the incubation period can be constant or intermittent. In certain embodiments a 15-minute incubation on ice is performed.
[0290] I) Centrifuging the Mixture
[0291] The mixture from H) is subjected to a centrifugation. The centrifugation typically forms a pellet and a supernatant, although pelleted material may not be visible to the eye. In contrast to the prior art, this centrifugation does not require ultracentrifugation, e.g., does not require centrifugal forces in excess of 100,000g. This centrifugation can be done at slower speeds, for example, to generate RCF values of not more than 30,000g, or not more than 20,000g, or not more than 12,000g, or not more than 10,000g, or not more than 5,000g, or not more than 2,000g, or not more than 1,500g. In the one embodiment, a centrifugation producing 2,000g is performed. The length of time for centrifugation is not limiting. In one embodiment, the centrifugation is for 5 minutes.
[0292] J) Removing the Supernatant
[0293] Following the spin, the resulting supernatant is carefully removed so not to disturb the pellet, and this supernatant is discarded.
[0294] K) Resuspending the Pelleted Material
[0295] After removal of the supernatant, the pellet is resuspended in any desired resuspension solution and collected for further analysis. The resuspension solution can use either water, phosphate buffered saline (PBS), or any other suitable aqueous, such as any isotonic solution. In some embodiments, the resuspension solution is basic nature, for example, 100 mM Tris pH 8. The volume used for the resuspension is most typically the smallest possible practical volume, and is typically many times smaller than the volume of the original liquid sample comprising the secreted microvesicles. In some embodiments, the volume of the resuspension solution is smaller by at least one order of magnitude than the volume of the original liquid sample.
[0296] While the above improved process describes an in vitro application of the current porous bead pre-clearing approach, it is also contemplated that such a pre-clearing approach could be used to improve, e.g., yield and/or purity of bioparticles during direct application of porous beads to a biofluid of a subject in vivo (e.g., using a first porous pouch or device containing porous beads that contacts a subject's mouth for pre-clearing of the subject's saliva, followed by application of a second porous pouch or device containing porous beads that contacts a subject's mouth and that is used for isolation of bioparticles from the subject's saliva).
Bioparticle Reduction in Biofluids of an Organism
[0297] The current disclosure provides for contact of biofluid of a subject with a composition containing porous beads capable of targeted sequestration and/or reduction of bioparticles from the contacted biofluid. Such compositions can optionally be implantable, and can include an outer, porous membrane and/or porous cellulose, mesh or other biocompatible layer, which surrounds or otherwise segregates the porous bead content from, e.g., surrounding tissues and/or cells, while allowing for bioparticles originally present in a biofluid to contact and be sequestered by the porous beads. Optionally, the composition containing the porous beads is a pouch or device bounded by a porous membrane and/or porous cellulose. In certain embodiments, the porous beads are siliceous beads, such as diatomaceous earth and/or perlite. Various implantable membranes, sacs and/or pouches that are contemplated as adaptable for use with the porous beads of the current disclosure have been described in the art, including at, e.g., EP 1466632; U.S. Pat. No. 8,591,531; U.S. Pat. No. 6,262,255; U.S. Pat. No. 5,713,888; and US 2014/0014226.
[0298] It is newly contemplated herein that undesired and/or deleterious signaling activities attributable to bioparticles that are present within a biofluid of an organism (e.g., within urine, saliva and/or other bodily fluids of a subject, in plants, or within growth media of cells in culture, including cells of animals single-celled organisms) can be disrupted simply via contacting of such biofluid(s) with porous beads (optionally contained within a biocompatible pouch and/or device) capable of sequestering and/or reducing the level of targeted bioparticles (e.g., EVs, e.g., exosomes) that are originally present in such biofluid(s).
Liquid Samples
[0299] The present disclosure provides methods, including improved methods, for isolating circulating bioparticles from liquid samples. The current disclosure also provides methods for sequestering and/or reducing circulating bioparticles within liquid samples. It is not intended that the nature of the liquid samples be in any way limited, and can be any liquid sample that contains bioparticles. Advantageously, very small volumes of liquid sample can be used and/or contacted, for example, as little as about 10 L, 50 L, 0.1 mL. 0.2 mL, 0.3 mL, 0.4 mL, 0.5 mL, 1.0 mL, or 2.0 mL, or 3.0 mL, or 5.0 mL of starting sample can be used.
[0300] In some embodiments, the liquid sample can be conditioned cell culture media that has been used to culture a cell line in vitro that has produced bioparticles, and therefore, those bioparticles are now contained in the conditioned media. The conditioned cell culture media can be a complete media (containing a serum supplement), or a serum-free culture media.
[0301] In some embodiments where the conditioned cell culture media is a complete media comprising a serum supplement, the serum supplement that is used can be a serum that has been depleted of any endogenous circulating bioparticles prior to addition of the supplement to the defined minimal growth media. The present disclosure also provides methods (including improved methods) for producing such bioparticle-depleted serum.
[0302] In some embodiments, the liquid sample and/or liquid that is contacted is a biofluid (synonymous with body fluid). The body fluid that is contacted with a composition of the current disclosure or used in an analysis and/or method of the current disclosure is not particularly limited. Bioparticles can be isolated from, sequestered and/or reduced within any body fluid using the methods of the current disclosure, even though a particular body fluid is not itemized herein, as it is intended that the present methods find use with any and all body fluids. For example, body fluids that can be contacted with, analyzed by and/or treated with the compositions or methods of the current disclosure include, but are not limited to, amniotic fluid, blood serum, blood plasma, breast milk, cerebrospinal fluid, lymph, mucus (including nasal drainage and phlegm), pericardial fluid, peritoneal fluid, semen, synovial fluid, tears, urine, sweat, saliva, and ascites fluid.
Crystallization/Precipitation Reagents (Solution 2)
[0303] In certain aspects, the present disclosure provides methods, including improved methods, for the isolation of bioparticles, including in certain embodiments for isolation of cf-nucleic acids, including ctDNAs, from liquid samples, in certain aspects, where the methods use a crystallization; precipitation solution (Solution 2), combined with the liquid sample, to initiate the bioparticles precipitation and isolation. Certain embodiments use Monosodium Urate in solid form, slurry form, or liquid form (solubilized in a basic solution such as NaOH). Another embodiment uses Uric Acid. Another embodiment uses some other salt of Uric acid. The amount used depends on the sample volume. One embodiment uses from 1 to 100 nM Monosodium Urate. Optionally, a Monosodium Urate or other crystallization/precipitation reagent at a concentration of 1, 2, 3, 4, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90 or 100 nM can be added to a sample in an amount of 5 L, 10 L, 20 L, 30 L, 40 L, 50 L, 60 L, 70 L, 80 L, 90 L, or 100 L or more, to promote a crystallization/precipitation event in the sample. It was discovered that Uric Acid and optionally Monosodium Urate when added to a liquid, optionally urine, crystallizes and induces a precipitate that includes bioparticles but excludes many proteins and salts contained in the liquid.
Matrix Reagents (Solution 2)
[0304] Certain aspects of the instant disclosure provide methods (including improved methods) and compositions for isolating, sequestration and/or reduction of bioparticles that, without wishing to be bound by theory, appear to exploit pore sizes of certain materials to effect bioparticle enrichment, such as the pore sizes found in porous beads, such as siliceous beads or particles, examples of which include diatomaceous earth (DE) and perlite. In certain embodiments, the porous beads (e.g., porous siliceous beads) are non-calcinated, non-acid washed, (i.e. natural grades) diatomaceous earth with average pore sizes ranging from 0.1 to 10 microns and permeabilities less than 2 darcies. In some embodiments, the porous beads (e.g., porous siliceous beads) are Perlite (i.e. treated volcanic glass) with pore sizes from 0.1 to 10 microns and permeabilities less than 2 darcies. It is contemplated that matrix reagents with average pore sizes in the range of 0.01 micron to 50 microns, including in the range of 0.01 to 1 micron, 0.5 to 40 microns, 0.5 to 50 microns, 1 to 20 microns, 1 to 10 microns, 2 to 5 microns, and/or about 3, 4, and/or 5 microns are effective reagents for isolation of microvesicles/bioparticles as described herein. Similarly, it is contemplated that agents with permeabilities of less than 5 darcies, less than 2 darcies, less than 1 darcy, less than 0.5 darcies, less than 0.3 darcies, or smaller can be effective reagents for the methods and compositions of the current disclosure. Exemplary grades of DE are non-calcinated, non-acid washed, natural forms possessing pore sizes between 0.5-2 microns in diameter and permeability below 0.1 Darcies (
EXAMPLES
[0305] The following examples are offered to illustrate, but not limit, the claimed invention.
[0306] It is understood that various modifications of minor nature or substitutions with substantially similar reagents or components will be recognizable to persons skilled in the art, and these modifications or substitutions are intended to be included within the spirit and purview of this application and within the scope of the appended claims.
[0307] Cell-free membrane and/or protein-containing structures found in urine have high value as biomarkers for disease or disorder diagnosis, and even for approaches involving screening of urine for therapeutic targets (e.g., biomarker and/or targetable miRNAs). Cell-free biomarkers are preferred agents to work with because they are relatively easy to isolate, are less variable in content/consistency than whole cells and/or whole cell-containing fluids, and can travel from the tissue of their origin into easy to isolate biofluids, such as urine (
[0308] A number of methods have been implemented and/or proposed for isolating microvesicles (MVs) from urine; however, all have significant limitations (
[0309] 1. Certain methods require expensive equipment (e.g., ultracentrifuge methods);
[0310] 2. Certain methods require expensive kits (e.g, NEP, Qiagen, Exiqon);
[0311] 3. Certain methods are difficult to scale up (e.g., Norgen (only a 1 ml column), ultrafiltration filters (e.g., Atnicon) can clog
[0312] 4. Many such methods are time consuming ultracentrifuge methods, SBI, Lifetech, Exiqon);
[0313] 5. Certain methods produce low yield, especially from certain fluids, such as urine (e.g., NEP, SBI, Lifetech, Exiqon);
[0314] 6. Certain methods use phenol (e.g., Lifetech).
[0315] An unmet need was thus previously identified for isolation of bioparticles (e.g., microvesicles, exosomes, etc.) from urine, as well as other bodily fluids (e.g., saliva, as well as blood, plasma, etc.), which has been improved upon in certain of the below examples. The instant methods (including certain improved methods) were newly identified to allow for rapid and inexpensive isolation of extracellular membrane particles, including microvesicles, exosomes and apoptotic bodies. The methods described herein were also observed to isolate membrane-free protein-nucleic acid particles as well. Finally, obtaining and in some cases dramatically improving yield of intact bioparticles is an advantage of the current disclosure, with such bioparticles used in mechanistic, vaccine- and delivery-related and therapeutic studies.
[0316] One advantage of certain of the currently described methods is that they use common laboratory reagents and apparatuses, and do not require high-speed centrifugation (e.g., use of an ultracentrifuge). Thus, the current methods are designed to achieve a higher yield than previously available methods, also allowing for isolation of important biomarkers and/or therapeutic targets from a smaller volume of sample than could be obtained using previously described approaches.
[0317] Bioparticles, particularly extracellular vesicles (EVs), including exosomes, have also recently been identified as important signaling moieties during initiation/establishment and/or progression of certain diseases and disorders, including hyperproliferative diseases such as cancer. Porous beads were previously identified (PCT/US2015/043768) as capable of isolating a range of bioparticles from contacted biofluids.
[0318] Certain aspects of the current disclosure therefore contemplate administration of porous bead compositions directly to a subject or organism, to cause sequestration and/or reduction of signaling bioparticle levels within a biofluid of a contacted subject, for advantageous, e.g., therapeutic, effect.
Development of Systems for Isolation of Circulating Bioparticles
[0319] Being unsatisfied with current methods for the isolation of circulating bioparticles, including exosomes, from urine and other biofluids, the following experiments were initiated and undertaken in an effort to develop new and improved methods for this purpose.
[0320] It was known that urine contains several constituents (chemicals) that can be present at saturating concentrations and thus can form crystals in vivo and in vitro and also can be easily precipitated from a urine sample in vitro. Since it was also known that certain crystals can form on and/or interact with epithelial cell membranes in the urinary tract, it was hypothesized, since microvesicles are membrane structures as well, that crystal growth on microvesicles could be induced artificially and then the microvesicle-crystal complex could be easily centrifuged out of solution as a method for microvesicle purification. Similarly, it was noticed while working with urine that the same group of endogenous chemicals present at near saturation levels, often spontaneously precipitated in vitro when exposed to lower temperatures and/or artificial concentration. It was hypothesized that artificially increasing the levels of some of these constituents could reliably induce a precipitate that would include bioparticles. It was also realized that the addition of these constituents of the urine approach to other liquids containing bioparticles (e.g., saliva, blood, plasma, etc.) would similarly crystallize/precipitate bioparticles (as was demonstrated in Example 3 below).
[0321] After an extensive trial and error process that examined different constituents of urine, it was discovered in certain embodiments that the addition of Monosodium Urate, but also optionally (additionally and/or alternatively) Uric Acid, or other salts of Uric Acid could indeed induce a crystallization/precipitation of urine and that the resulting sediment of this included biomarkers known to be present in microvesicles and cell-free protein-nucleic acid complexes.
Example 1
A Recently Discovered Na Urate Protocol Isolated Microvesicles from Urine Quickly and Effectively
[0322] To exemplify certain recently discovered methods for microvesicle and bioparticle isolation, 21 ml whole urine samples obtained from two different donors (one sample was naturally concentrated and one sample was naturally dilute) were treated with 16 mM TCEP reducing agent as part of a Whole Urine Prespin Treatment Solution, which simultaneously reduced the pH to <6 and was believed to have reduced the matrix-forming properties of the abundant endogenous urine protein, THP. The mixture was immediately centrifuged at 1,000g for 5 minutes to remove cells and debris. The supernatant was gently removed and then 40 microliters of 131 mM Monosodium urate (in 1 N NaOH) was added to create a mixture. This mixture was incubated for 15 minutes on ice and then centrifuged for 5 minutes at 1,000g in a desktop microcentrifuge. After centrifugation, the supernatant was gently removed. and the pellet was resuspended in a small volume of PBS buffer.
[0323] At the same time, using the same samples, bioparticles were isolated using the gold standard method of Ultracentrifugation using a published protocol (Fernandez-Llama Tamm-Horsfall Protein and Urinary Exosome Isolation (2010) Kidney Int. 77:736-742), as well as with three commercial precipitation kits (SBI, Life Technologies, and Exiqon), following their protocols. The instant method took 25 minutes, as compared to 2.5 hours for ultracentrifuge, 14 hours for SBI, 2 hours for Exiqon and 3 hours for Life Technologies. The instant method required no special equipment, while the Ultracentrifuge method requires a $35,000 ultracentrifuge and rotor. The commercial methods all required an expenditure of between $2 to $10, while the instant method required approximately 1 penny worth of Monosodium urate.
[0324] Protein biomarkers for microvesicles were assayed for all of the above preparations. As shown in
[0325] To ascertain if the instant method was consistently superior to other methods for more dilute urine samples, the instant method, UC, and commercial kits obtained from Exiqon and SBI were applied to two mls of a single concentrated sample, or to the same sample diluted with PBS 2, 4, or 8. As shown in
[0326] To determine if the instant method was indeed purifying bioparticles from urine, that is, if there was less protein in the instant method prep than in the starting sample, a urine sample was split in two with half of the sample concentrated by an Amicon protein purification column (Ultra-15; ultracel-3K) and the instant method applied to the other half. Equivalent amounts of the resulting preps were loaded onto a SDS PAGE gel and the protein on the gel was stained with Coomassie stain.
[0327] To assess the quality of biomarkers isolated by the newly-identified Na Urate process, isolated RNA from such preparations was examined, particularly miRNA. As shown in
[0328] It was important for downstream analysis that a given method did not co-purify PCR inhibitors with the RNA. To test for this, isolated bioparticles prepped by the instant method or by ultracentrifuge were spiked with the non-endogenous microRNA cel-mir-39 from c. elegans, and then PCR was performed using probes specific for this microRNA. If the instant method introduced PCR inhibitors to a greater extent than the gold standard ultracentrifuge method, then a lower amount of cel-mir-39 would have been detected for the instant method as compared to ultracentrifuge. Since an identical amount of cel-fair-39 was detected in both methods,
[0329] It was highly desirable to isolate whole microparticles, rather than just RNA or protein from microparticles. Whole microparticles can be used for functional experiments directed towards therapeutic discovery (De Toro et al. Emerging roles of Exosomes in Normal and Pathological Conditions: New Insights for Diagnosis and Therapeutic Applications. (2015) Front. Immunol. 6:203). They also can be used as a delivery agent for therapeutic and research payloads (Tran et al. Exosomes as Nanocarriers for Immunotherapy of Cancer and Inflammatory Diseases. (2015) Clin Immunol. PMID: 25842185). To determine if the instant method isolated whole microparticles, Transmission Election Microscope and a Nanosight nanoparticle tracking analysis (NTA) device were employed. The Nanosight device used lasers to visualize and track the Brownian motion of individual particles (Dragovic et al., Sizing and phenotyping of cellular vesicles using Nanoparticle Tracking Analysis, Nanomedicine: Nanotechnology, Biology and Medicine (2010, doi:10.1016/j.nano.2011.04.003). This allowed for obtainment of precise size and concentration data for the isolated microparticles.
[0330] If the instant method degraded or altered the microparticles significantly, then the size and/or shape of the vesicles would have been predicted to appear different when compared to UC isolated vesicles by Transmission Electron Microscopy.
[0331] One of the drawbacks of isolating bioparticles using Ultracentrifugation, binding columns, and/or sieving columns is that there are substantial labor and expense costs when scaling up to larger volumes (i.e. many more ultracentrifugation runs and many more expensive columns are required for larger volumes, as each ultracentrifugation tube and column could only hold a small amount of sample). Therefore, it was of interest to determine if the instant method linearly scaled to larger volumes of urine for both protein and RNA bioparticle markers.
[0332] As shown n
Example 2
The Na Urate Process More Completely Depleted Urine of Bioparticles than the Ultracentrifuge Method
[0333] The fact that the instant Na Urate method isolated significantly more of several protein and microRNA markers for bioparticles, and also of particles as judged by NTA and TEM (see Example 1 above), strongly suggested that the instant method could isolate the same bioparticles which the heretofore gold standard method of ultracentrifugation could. This was important, as there was also value in depleting biofluids such as urine, blood serum/plasma, and tissue culture serum of bioparticles. To determine if the instant method more completely depleted urine of bioparticles than the ultracentrifuge method, the instant method and the ultracentrifuge method were applied to 1.5 mls of urine from the same sample. Subsequently, the respective final supernatants for each method represented bioparticle-depleted urine. These depleted urine samples were then applied to the alternate method (i.e. the instant method was applied to the ultracentrifuge supernatant and the ultracentrifuge method was applied to the instant method supernatant).
Example 3
The Na Urate Process Isolated Bioparticles/Microvesicles From Non-Urine Biofluids
[0334] To determine if the instant method could isolate bioparticles from liquid other than urine, bioparticles were initially isolated from 1 ml of urine using ultracentrifuge. These bioparticles were then added to pure water, and the instant method was applied. This was considered to be an ideal test for the hypothesis that the instant method could isolate bioparticles from other fluids, because water contains no salt, has a neutral pH, and also has no other constituents of urine. As
Example 4
The Efficiency of the Na Urate Purification Methods Enabled Use of 96 Well Format Plates for High-Throughput Bioparticle Isolation
[0335] Given the ability of the methods of the recently described approach to isolate significant amounts of extracellular vesicle markers from 1 ml and lower amounts of urine sample (See
Example 5
Alternative Urate/Uric Acid Compositions were Identified as Effective for Bioparticle Isolation from Urine and Other Biofluids
[0336] While the above experiments were primarily performed using sodium urate (Na Urate) to promote biomarker/microvesicle isolation from urine, a range of uric acid salts also capable of isolating such biomarkerslmicrovesicles was also identified. As shown in
Example 6
Uric Acid Compositions Isolated DNA
[0337] To exemplify certain methods of the current disclosure, 50 mls whole urine samples obtained from a healthy volunteer were split into 2 equal 25 ml aliquots. Aliquot 1 was treated with 16 mM TCEP reducing agent, as part of a Whole Urine Prespin Treatment Solution, which simultaneously reduced the pH to <6 and was believed to have reduced the matrix-forming properties of the abundant endogenous urine protein, THP. The mixture was immediately centrifuged at 1,500g for 5 minutes to remove cells and debris. The supernatant was gently removed and then 40 microliters per ml of sample of 131 mM Monosodium urate (in 1 N NaOH) was added to create a mixture. This mixture was incubated for 15 minutes on ice and then centrifuged for 5 minutes at 1,000g in a desktop microcentrifuge. After centrifugation, the supernatant was gently removed and the pellet was resuspended in a small volume of PBS buffer. Aliquot 2 was also treated with 16 mM TCEP reducing agent, and the cells and debris were spun out as per Aliquot 1. The resulting supernatant was spun through an Amicon MWCO 3000 column to concentrate it. Both resulting concentrated Aliquots then were run through an Ambion mirVANA RNA isolation kit to isolate nucleic acids. The nucleic acids were subjected to PCR analysis, in the absence of reverse transcription, to determine the relative amounts of GAPDH DNA fragments contained in the preps (see
[0338] Thus, the crystallization/precipitation-inducing agent method was identified as especially effective for isolation of cell-free nucleic acids, and for cfDNA in particular (including, e.g., ctDNAs).
Example 7
Diatomaceous Earth Isolated Vesicle Protein Markers from Urine, While Control Silica Did Not
[0339] Following extensive searches for conditions that could exploit the association of large, matrix-forming proteins such as THP with exosomes for bioparticle purification, it was initially discovered that addition of the robust reducing agent TCEP within a pre-spin centrifugation of urine samples could allow for improved removal of whole cells in initial clearing spins from urine, while retaining exosomes within the supernatant of such spins (
[0340] DE is characterized by a nanometer) micrometer-range pore sizes. To examine if non-DE porous materials (i.e., Perlite, which is volcanic glass heated to expand and form pores) were also capable of isolating biomarkers/microvesicles, such agents were examined within the recently described methods. As shown inn
[0341] The products of DE-directed bioparticle/microvesicle isolations were also examined for the integrity of RNA (i.e., miRNAs) within such preparations. As shown in
[0342] Furthermore, it was hypothesized that a brief (typically 1 minute) preliminary treatment or preclear of DE would remove potential molecular constituent binders to DE from the biofluid, which could block subsequent binding of bioparticles to DE. Thus, following this new preclear step with any of standard protocols (e.g., a second round of contacting a sample with porous beads, e.g., for 15 minutes) would yield superior results.
Example 8
Combination of the Na Urate and Diatomaceous Earth Processes Significantly Increased Bioparticle Yield, as Compared to the Na Urate Method Alone
[0343] Without wishing to be bound by theory, the hypothesized mechanisms of action for the two methods described above (crystallization/precipitation and binding to a porous siliceous matrix) are sufficiently distinct to suggest that they could work simultaneously and possibly even more efficaciously. To test this, a 20 ml urine sample was divided into 2 equal 10 ml aliquots. To aliquot 1, the same Na Urate protocol described in Example 1 was applied. To aliquot 2, 1 ml of DE in a 10% DE slurry in PBS, 150 mM NaCl was added to the sample after the prespin, then the same Na Urate protocol was applied without deviation. Nucleic acids of the resulting pellets from both aliquots were then purified by glass fiber filtration and then subjected to TaqMan chemistry to detect miRNA and GAPDH nucleic acids.
[0344] Thus, a combined method of contacting a biofluid with both porous beads and a crystallization/precipitation was identified to result in improved yields, as compared to either method alone. Such a combined method could also optionally be performed after a pre-clearing step with a porous bead, as described above, though the improvement inherent in the combined method was even observed without performing a pre-clearing step of certain improved methods of the current disclosure.
[0345] Accordingly, a high speed, low cost and highly efficient method of isolating bioparticles from multiple biofluids was identified, representing a dramatic improvement over methods previously described in the art.
Example 9
Use of Porous Beads to Reduce Levels of Bioparticles in Biofluids
[0346] A broad range of biomarkers are secreted from cells, such as miRNA, proteins, lipids, glycoproteins, DNA, mRNA, tRNA, etc., which can exist in relatively stable form outside of cells, including but not limited to the following forms: protein-nucleic acid complexes, exosomes, microvesicles, LDL particles, and apoptotic bodies (
Example 10
DE Placed in a Porous Container and Introduced to the Mouth of a Subject Isolated Exosomes
[0347] As shown in
Example 11
Therapeutic Reduction of Bioparticles in Urine of a Subject Having or at Risk of Developing Bladder Cancer
[0348] In an exemplary therapeutic method of the current disclosure, a subject having or at risk of developing bladder cancer is identified. Porous beads, e.g., DE, are deposited in a porous, implantable membrane-bounded pouch or device. The implantable pouch or device is inserted into the bladder of the subject, optionally at or near a site of an existing tumor, and in contact with the urine of the subject. The device remains implanted in the subject for an appropriate period of time (e.g., ranging from a single day to a number of months or even years, noting the inert/non-toxic nature of both the implantable pouch or device and its contents (e.g., DE)). Growth, progression and/or metastasis of cancer (or markers of pro-cancer signaling) in the subject is assessed, using art-recognized methods, relative to an appropriate control subject or value, and the therapeutic efficacy of the implantable pouch or device containing the porous beads (e.g., DE) is thereby assessed.
[0349] Optionally, the implantable pouch or device is removed from the subject, and sequestered biomarkers are examined (either via dissociation from the porous beads or via detection methods that do not require such dissociation). Therapeutic, diagnostic and/or prognostic associations and/or conclusions are detected using the isolated biomarkers.
Example 12
Prophylactic and/or Therapeutic Reduction of Bioparticles in Saliva of a Subject Having or at Risk of Developing Oral Cancer
[0350] In an exemplary prophylactic and/or therapeutic method of the current disclosure, a subject having or at risk of developing oral cancer (e.g., a tobacco user) is identified. Porous beads, e.g., DE, are deposited inn a porous pouch or device. The pouch or device is inserted into the mouth of the subject, optionally at or near a site of an existing growth/tumor, or simply between the cheek and gum, contacting saliva of the subject. The pouch or device remains in the subjects mouth for an appropriate period of time (e.g., minutes to hours or longer, optionally co-administered with a dose of tobacco), noting the inert/non-toxic nature of both the pouch or device and its contents (e.g., DE)). Markers of pro-cancer signaling and/or growth, progression and/or metastasis of cancer in the subject is assessed (optionally over multiple administrations of a pouch or device of the current disclosure), using art-recognized methods, relative to an appropriate control subject or value, and the prophylactic and/or therapeutic efficacy of the pouch or device containing the porous beads (e.g., DE) is thereby assessed.
[0351] Optionally, following contact with and removal from the subject, biomarkers sequestered within the pouch or device are examined (either via dissociation from the porous beads or via detection methods that do not require such dissociation). Therapeutic, diagnostic and/or prognostic associations and/or conclusions are made via detection of the isolated biomarkers.
[0352] All patents and publications mentioned in the specification are indicative of the levels of skill of those skilled in the art to which the invention pertains. All references cited in this disclosure are incorporated by reference to the same extent as if each reference had been incorporated by reference in its entirety individually.
[0353] One skilled in the art would readily appreciate that the invention is well adapted to carry out the objects and obtain the ends and advantages mentioned, as well as those inherent therein. The methods and compositions described herein as presently representative of preferred embodiments are exemplary and are not intended as limitations on the scope of the invention. Changes therein and other uses will occur to those skilled in the art, which are encompassed within the spirit of the invention, are defined by the scope of the claims.
[0354] It will be readily apparent to one skilled in the art that varying substitutions and modifications can be made to the invention disclosed herein without departing from the scope and spirit of the invention. Thus, such additional embodiments are within the scope of the invention and the following claims.
[0355] The invention illustratively described herein suitably can be practiced in the absence of any element or elements, limitation or limitations that are not specifically disclosed herein. Thus, for example, in each instance herein any of the terms comprising, consisting essentially of, and consisting of may be replaced with either of the other two terms. The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention that in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. Thus, it should be understood that although the invention has been specifically disclosed by preferred embodiments, optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention as defined by the description and the appended claims.
[0356] In addition, where features or aspects of the invention are described in terms of Markush groups or other grouping of alternatives, those skilled in the art will recognize that the invention is also thereby described in terms of any individual member or subgroup of members of the Markush group or other group.
[0357] The use of the terms a and an and the and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms comprising, having, including, and containing are to be construed as open-ended terms (i.e., meaning including, but not limited to,) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., such as) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
[0358] Embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description.
[0359] The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims.