ATRAUMATICALLY FORMED TISSUE COMPOSITIONS, DEVICES AND METHODS OF PREPARATION AND TREATMENT
20230018416 · 2023-01-19
Assignee
Inventors
- Thomas Andrew Davenport (Syosset, NY, US)
- Paul Mulhauser (New York, NY, US)
- Gregory C. Guinan (Brooklyn, NY, US)
Cpc classification
A61L27/3695
HUMAN NECESSITIES
C12M45/02
CHEMISTRY; METALLURGY
A61L27/3691
HUMAN NECESSITIES
C12M45/04
CHEMISTRY; METALLURGY
A61B2017/320024
HUMAN NECESSITIES
International classification
A61L27/36
HUMAN NECESSITIES
Abstract
A process and system provides for atraumatic preparation of morselized Tissue Particles (TP)s, such as Full Thickness Skin Graft Particles (FTSGPs), cartilage particles and other organ tissue particles, in a liquid medium. The resultant tissue product may be a suspension of Tissue Particles in an aqueous solution and containing highly viable cells and may be rapidly prepared at bedside or in the operating room and conveniently delivered to a patient through a syringe or similar applicator. The morselized Tissues Particles may be used for surgical applications including wound healing, cosmetic surgery, and orthopedic cartilage repairs.
Claims
1. Morselized tissue particles, having an average diameter of about 0.20 mm to 1.50 mm, and a viability of at least 60%.
2. The morselized tissue particles of claim 1, wherein the morselized tissue particles are morselized cartilage tissue particles.
3. The morselized cartilage tissue particles of claim 2, wherein an average size as measured across a largest dimension is selected from the group consisting of: about 0.35 mm to 1.25 mm, about 0.5 mm to about 1.00 mm, about 0.5 mm to about 0.75 mm, about 0.25 mm to about 0.75 mm, and about 0.50 mm.
4. The morselized cartilage tissue particles of claim 2, wherein the viability is at least 85%.
5. The morselized cartilage tissue particles of claim 2, wherein the viability is selected from the group consisting of: at least 90%, at least 92%, at least 94%, at least 96%, at least 97%, at least 98%, at least 99%, and 87-98%.
6. The morselized cartilage tissue particles of claim 2, wherein an average size as measured across a largest dimension is about 0.25 mm to 0.75 mm, and wherein the viability is at least 90%.
7. The morselized cartilage tissue particles of claim 2, wherein an average size as measured across a largest dimension is about 0.50 mm.
8. A composition comprising the morselized cartilage tissue particles of claim 2, wherein the composition is in a form selected from the group consisting of a liquid, suspension, dispersion, cream, fluid, emulsion, paste, spray, and injectable.
9. The composition of claim 8, further comprising at least one selected from the group consisting of a liquid medium, fibrin glue, autologous platelet rich plasma, growth factors, binders, saline, buffer solution, and cell nurturing/preservation solution.
10. The composition of claim 9, wherein the liquid medium is a hydrophilic medium, an oleophilic medium, or an emulsion of hydrophilic and oleophilic mediums.
11. The composition of claim 8, wherein the composition is in the form of a suspension, further wherein the suspension is heterogeneous.
12. The composition of claim 8, wherein the composition is in the form of a suspension, further wherein the suspension is homogenous.
13. A method of repairing cartilage or treating a cartilage defect in a patient in need thereof, comprising administering the composition of claim 8 to the patient.
14. The method of claim 13, wherein the composition is administered to a joint of the patient.
15. The method of claim 13, wherein the composition is administered to the patient via syringe or spatula.
16. Morselized tissue particles, having an average size as measured across a largest dimension of about 0.25 mm to 0.75 mm, and a viability of at least 60%.
17. The morselized tissue particles of claim 16, wherein the viability is at least 70%.
18. The morselized tissue particles of claim 16, wherein the viability is at least 85%.
19. The morselized tissue particles of claim 16, wherein the morselized tissue particles are morselized cartilage tissue particles.
20. The morselized cartilage tissue particles of claim 19, wherein the viability is at least 85%.
21. The morselized cartilage tissue particles of claim 19, wherein the viability is at least 92%.
22. The morselized cartilage tissue particles of claim 19, wherein the viability is at least 96%.
23. The morselized cartilage tissue particles of claim 19, wherein the viability is 87-98%.
24. The morselized cartilage tissue particles of claim 19, having an average size as measured across a largest dimension of about 0.50 mm and a viability of at least 90%.
25. A composition comprising the morselized cartilage tissue particles of claim 19, wherein the composition is in a form selected from the group consisting of a liquid, suspension, dispersion, cream, fluid, emulsion, paste, spray, and injectable.
26. The composition of claim 25, wherein the morselized cartilage tissue particles have an average size as measured across a largest dimension of about 0.50 mm.
27. The composition of claim 25, further comprising at least one selected from the group consisting of a liquid medium, fibrin glue, autologous platelet rich plasma, growth factors, binders, saline, buffer solution, and cell nurturing/preservation solution.
28. A method of repairing cartilage or treating a cartilage defect in a patient in need thereof, comprising administering the composition of claim 25 to the patient.
29. The method of claim 28, wherein the morselized cartilage tissue particles have an average size as measured across a largest dimension of about 0.50 mm.
30. The method of claim 28, wherein the composition is administered to a joint of the patient.
31. The method of claim 29, wherein the composition is administered to a joint of the patient.
32. The method of claim 28, wherein the morselized cartilage tissue particles is morselized articular cartilage tissue particles.
33. The morselized cartilage tissue particles of claim 2, wherein the source of the cartilage tissue is non-articular cartilage, articular cartilage, or a combination thereof.
34. A cartilage graft, comprising the morselized cartilage tissue particles of claim 2.
35. A surgical procedure comprising: harvesting at least one tissue portion from a patient; processing the harvested tissue for less than 1 hour to prepare morselized tissue particles, wherein the morselized tissue particles have an average size as measured across a largest dimension of about 0.25 mm to 0.75 mm and a viability of at least 85%; and implanting the morselized tissue particles in a joint of the patient.
36. The surgical procedure of claim 35, wherein: the at least one tissue portion is at least one cartilage tissue portion, the harvested tissue is harvested cartilage, and the morselized tissue particles are morselized cartilage tissue particles.
37. The surgical procedure of claim 36, wherein the harvested cartilage is harvested from the patient's non-articular cartilage or articular cartilage.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
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DETAILED DESCRIPTION OF THE INVENTION
[0070] The device has features which optimize processing cell viability and convenience of tissue handling and transfer. Specifically, the aqueous processing allows for temperature, pH, and salinity control of the processing which would ideally be variable depending on the tissue, isotonic factors. The pH may be controlled with physiologic buffers. The variable blade speed allows for control of any potential baro-trauma caused by the formation of the vortex, which repeatedly moves the tissue suspended in the aqueous medium through the cutting devices.
[0071] The selection of ultra-sharp cutting blades is one important factor in ensuring that the tissue that is morselized remains viable. The use of pH controlled aqueous medium, along with the ability to control the temperature of the medium during processing, as well as, the time, are also important factors in achieving morselization with the exceptionally high degree of viability of the invention.
[0072] Mass-produced disposable razor blades and microtome blades are among the sharpest steel blades in the world. Razor type blades are typically martensitic stainless steel with a composition of chromium between 12 and 14.5% and a carbon content of approximately 0.6%. The high-volume linear process to produce such blades, starts with a roll formed strip of controlled thickness that is run as a ribbon through a continuous manufacturing process. The linear manufacturing process enables exceptionally tight and repeatable control of multiple sequenced automated processes including, for example, grinding multiple distinctly stepped beveled/faceted cutting blade edges on both sides; with cutting edges as thin as 30 nm for razor blades and 3 nm for microtome blades; with edges fortified with separate vacuum chamber applied hardened coatings (for example titanium+manmade diamond to harden edge), followed by, for example low friction polymer film for slipperier edge. Individual blades are progressively die-stamped in-line in a repeatable manner.
[0073] Blade Sharpness, is absolutely necessary to minimize cell mastication. Use of ultra-sharp blades, passing through and between masses of live cells, and through interstitial spaces, best assures a narrow margin of violated cells along the cut line with the least amount of shear forces and crushing of cells. Slicing of tissue between two blade edges, passing at acute angles, enables stabilization of the tissue throughout each cut to achieve controlled atraumatic slicing of whole thickness skin tissue into morselized particles.
[0074] Use of ultra-sharp blades, as achievable through automated processes, assures repeatability and expedites the morselization process, enabling autologous whole thickness skin to be quickly converted into a new morselized implantable tissue particles within minutes.
[0075] To maintain cell viability, best practice is to keep the harvested tissue wetted and then suspended in the pH controlled solution throughout handling (i.e. in saline, a buffer solution, or BioLife Solution®, or other cell nurturing/preservation solutions, etc.).
Detailed Description of Devices
[0076] One preferred embodiment for morselizing full thickness skin grafts (FTSGs) supported in a sterile fluid is shown generally in
[0077] Processing device 10 includes a liquid-tight container 12 having an open upper end 14 which may be suitably enclosed by a cover 16. The cover 16 has an inlet aperture 18 which allows for insertion of tissue into the fluid. In a preferred embodiment the container is generally cylindrical having a closed curved bottom 20 opposite open upper end 14 with and exit opening 17 therein. While the cover 16 and the container 12 may be made of various materials, in a preferred embodiment, the cover and container are formed of a suitable plastic such as polypropylene (PP), polyethylene (PE), polystyrene (PS), polyethylene terephthalate (PET), polyimide (PA), acrylonitrile butadiene (ABS), polyetheretherketone (PEEK) and polyurethane (PU). Combinations or co-polymers of these polymers may be used. Glass, ceramic or metal containers may also be used. The container 12 may be transparent to visualize the processing and quality of the fluid and tissue being processed within.
[0078] An additional removable or adjoined protective cover that is able to be manually opened and closed may be included so as to close off the cover opening during processing to best assure containment of fluid and cellular contents.
[0079] It is also contemplated that all components comprising the overall processing device, including the container and morselizing mechanism, isolation device and applicator will be packaged and bulk sterilized, for single-patient use and disposable. The packaged devices may be irradiated with gamma or e-beam or ethylene-oxide (EtO). Alternatively, the processing device may be sterilizable and reusable.
[0080] Extending from bottom 20, container 12 includes a generally elongate tubular conduit 22 in fluid communication with the interior 13 of container 12 through opening 17. The conduit terminates in a container mount 24 at the lower end thereof. Extending outwardly and in fluid communication with conduit 22 is an outlet 26 which in the preferred embodiment shown in
[0081] Cover 16 is movably supported at the open upper end 14 of container 12 for movement along a central axis A. The upper end 14 of container 12 includes, for example, an outwardly directed key 12a which is seated in a slot 16a in adjacent skirt 16b cover 16. The key 12a is movable along axis A within the slot 160 to allow for the movement of the cover 16 with respect to the container 12, while restricting cover 16 rotation about axis A.
[0082] The cover 16 further includes an inwardly formed downwardly extending generally tubular stem 28 having an upper cup-shape cavity 30 covered by a cap 31. The stem 28 accommodates a mounting rod 32 having a threaded lower end 34 and an upper end 36 terminating in an enlarged head 38. The head 38 is captively retained within the cavity 30 supported by a spring 39, for example by one or more Belleville, dome, single or multiple wave type washers, captive between the lower end of cavity 30 and the enlarged head 38. The spring or springs 39 may additionally be captively sandwiched between conventional type washers 39b, the threaded lower end 34 of rod 32 is threaded into impeller 108 about axis A. A shoulder 32b, adjacent to threaded end 34 of rod 32, is supported against impeller 108.
[0083] A disk shaped stationary cutting member 102 is supported upon the terminus of stem 28 on a perpendicular plain relative to axis A. The stationary cutting member 102 is constrained from rotating about axis A by, for example, mating pins 28a or other keyed features in engagement between the stem 28 and the stationary cutting member 102.
[0084] Now as best shown by
[0085] Referring particularly to
[0086] As described in further detail below the drive shaft 42 is attached to an operatable processor 44 shown schematically in
[0087] The processor 44 is preferably a reusable device that is configured for ease of being aseptically cleaned following each use. The processor 44 is also configured to replaceably receive a processing device 10 in mechanical engagement in such manner that enables a user to attach, use, and remove the processing device using standard practices for interfacing surgical devices in a sterile field. The processor 44 may also be configured to receive a sterile drape to isolate surfaces not shrouded by a coupled processing device. The processor may also be a device that is entirely sterilizable and/or powered by compressed air that is easily available in the operation room setting.
[0088] As shown in
[0089] As is shown in
Morselizing Mechanism
[0090] Operative components of morselizing mechanism 40 are shown in further detail with additional reference to
[0091] Morselizing mechanism 40 includes a base component 100 and a stationary cutting member 102 which are axially aligned over one another along axis A. Base component 100 is mounted to the drive shaft 42 with a depending mount 104 to provide for rotation. Above mount 104 is a flat circular plate 106 which is generally transverse. Plate 106 also serves as the seating surface in opening 17 of the bottom 20 of container 12 as is shown in
[0092] The upper end of base component 100 serves as an impeller 108 having two or more impeller vanes 110 upwardly extending from plate 106 on diametrically opposed sides of axis A. The impeller vanes 110 are each curved along axis A in a complimentary fashion for purposes that will be described in further detail below. Each impeller vane 110 supports in facing relationship at the upper end a cutting blade 112. As also will be described in further detail below, the cutting blades 112 at the upper ends of impeller vanes 110 are supported in juxtaposition with the stationary cutting member 102. The blades 112 rotate with base component 100 with respect to stationary cutting member 102.
[0093] In a preferred embodiment shown in
[0094] In one embodiment shown in
[0095] In a more preferred embodiment shown in
[0096] The arrangement of the stationary cutting member 102 with respect to the impeller 108 is shown schematically in
[0097] The stationary cutting member 102 is preferably stainless steel and CNC machined with precision ground sharp burr free stationary blade edges 122. The bottom shearing plane (SP) surface must be flat and preferably 0.08 μm or better finish. The stainless steel material should generally be a corrosion resistant and hardened grade, for example 440C stainless steel, machined in annealed state and vacuum heat treated to 55-60 RC to achieve a hardened surface and durable sustainable cutting edges.
[0098] The rotating cutting blades 112 may be mounted at the upper end of the impeller 108 supported by a spring such as an elastomeric pad 130 which biases the edge of the cutting blade 112 against the lower edge of the disc shaped body 102a of stationary cutting member 102. It has been found that maintaining the cutting blade edges 112a in physical contact against the stationary cutting member 102, minimizes tearing and shredding of the tissue.
[0099] Referring to
[0100] The rotating cutting blades 112 are positioned at an acute cutting angle relative to the juxtaposed stationary blade edges 122, such that tissue, when captured between the rotating blades 112 and juxtaposed stationary blades 122 will be cut with a slicing action.
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[0102] The rotating cutting blade 112 is best arranged at an acute angle relative to the lower surface of the stationary cutting member 102, so that the tip of rotating blade cutting edge 112a passes at an acute angle with respect to the stationary blade edges 122 of blade surfaces 120.
[0103] As previously described above, springs 39 may be used to compressively pre-load the rotating blade edges 112a to maintain contact upon stationary blade edges 122 throughout rotation.
[0104] While in a preferred embodiment, the shear plane (SP) is normal to the chamber impeller and blade rotation access. The shear plane (SP) may also take other direction with respect to the axis A. One example is shown in
[0105] Also, in this embodiment, the rotor blades 242 have surfaces which are configured as integrally formed impeller vanes. The rotating edges may be generally co-extensive to the leading impeller vane edges. The rotating rotor blades and stationary stator blade edges should preferably remain in intimate physical contact to best achieve precise slicing. The blades may be machine honed for closely controlled minimum shear gap, preferably less than 30 micrometers. Positioning the rotating blade edges at an acute angle relative to the shear plane of stationary cutting blade edges facilitates a shear cut for the impinged tissue. Maintaining a spring assisted compressive engagement between the rotating blade edges and the shear plane of the opposing blade edges best assures that tissue will be precisely slice, rather than to slip between the converging blade edges.
[0106] Other techniques and arrangements for cutting the tissue at a shear plane may also be within the contemplation of one skilled in the art.
Tissue Morselization
[0107] Having described the basic components of the process device 10 of the present invention, one preferred example of the morselization of tissue or specifically TPs as defined herein will be described with respect to the Figures.
[0108] Initially, with reference to
[0109] Referring to
[0110] Shown schematically in
[0111] A person of ordinary skill in the art will be able to alternatively configure, for example, impeller vanes and/or internal container geometry and/or bottom 20 forms so as to enhance effective circulating flow of fluid with suspended tissue though-out the container 12 and through the morselizing mechanism 40. Internal flow characteristics may be enhanced, for example, by increasing or decreasing the pitch or otherwise reshaping the form of impeller vanes 110; or by increasing or decreasing the pitch of a portion of a vane configured for axial thrust 110a relative to the pitch of a portion of a vane configured for radial thrust 110b; or to eliminate either of the axial thrusting vane surfaces or radial thrusting vane surfaces.
[0112] Referring to
[0113] Upon completing the morselization of FTSG or other tissues grafts into TPs, the impeller 108 rotation may be stopped and the TPs, as defined herein, having a specific gravity greater than water, will settle to the bottom 20 of container 12. One skilled in the art will recognize that alternative methods may be used to manually withdraw the settled TPs from the bottom 20 of container 12 within the processing device 10. For example, the settled TPs may be drawn into a conventional syringe in combination with an elongated cannulated tip (not shown) that can be inserted into the container 12 through the inlet aperture 18. In such manner, the same syringe used to draw the TPs from the processor 10 could then be used as an application device. In this manner of manually drawing out the TPs through the inlet aperture 18, the processing device 10 need not include a drain 39 or an outlet 26.
Discharge of Morselized FTSGPs
[0114] Discharging the morselized Tissue Particles (TPs) or for example specifically FTSGPs, into an applicator 300 may now be described with respect to
[0115] The syringe applicator 300 also serves as a device to separate excess fluids from the TPs. A cylindrical screen filter 302 is formed as an insert to the applicator body 303 and has an inner applicator chamber 308 lumen to receive a plunger 304 and piston 306. Peripheral drain channels 305 may surround the filter 302 such that excess fluid within the morselized TPs may pass freely through the filter walls, through the drain channels 305 and out the drain outlets 310. The screen filter may encompass 360° of the applicator or only a portion thereof, as shown in
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[0117] The applicator 300 is shown with the plunger 304 and piston 306 in its raised position and with the cap 318 in place to close the dispensing orifice. As the TPs and solution enters the applicator 300, the fluid is drained away from the TPs as the fluid will freely pass through the filter walls 302, through the flow channels 305 and exit the applicator 300 through the drain outlet 310 into the fluid waste drain container 317. Thereafter, the plunger 304 may be advanced sufficiently into the applicator chamber 308 so as to enable the piston 306 to close off the port 320. The applicator 300 may then be removed from the processing device 10 by disconnecting inlet port 320 of the applicator 300 from the outlet port 26a of the processing device 10. Thereafter, the cap 318 may be removed from the applicator 300 and a selected applicator tip 301 may be affixed to the dispensing orifice 309 for dispensing the TPs in a manner which will be described in further detail hereinbelow.
[0118] A further embodiment of the present invention, shown in
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[0120] The motor speed is changed, as appropriate, to pump the solution and TPs through the outlet channel 26 and through a diverter valve 417 to enter a cylindrical isolation chamber 416 containing a cylindrical filter tube 402 lining. The filter tube 402 may be, for example a woven mesh, perforated film or acid-etched screen with openings sized appropriately to capture particularly desired sized TPs. The particles are captured within the isolation chamber 416 as fluid passes through the filter tube, and through circumferential drain channels 405, exiting the isolation device 415 through inlet conduit 29, to return into the container 12 of processing device 10. Within several brief passes the motor 114 will automatically stop as the TPs are substantially rinsed away from the container 12 and transferred into the isolation device 415.
[0121] The diverter valve 417 may then be automatically or manually switched, for example turned 90° clockwise, to open a fluid path from the isolation chamber 416 into the applicator 400. The inlet conduit 29 is positioned below the fill line (F) of container 12, enabling the head pressure of contained fluid to substantially flush the TPs from the isolation chamber 416 through the diverter valve 417, through an applicator attachment 411, and into the applicator chamber 408 of a detachable applicator 400.
[0122] Thereafter, the diverter valve 415 is closed; the applicator 400 is disconnected from the applicator attachment 411; and a plunger with piston (as shown for example in previous
[0123] The processing device 10, isolation device 415 and applicator 400 may be packaged as an integral sterile assembly. Applicators 400 may alternatively be sterile packaged separately.
[0124] Turning now to
[0125] A still further embodiment is shown in
[0126] A still further embodiment is shown in
[0127] The schematically drawn circulating flow (CF) paths in
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[0129] Although the circulating flow (CF) paths within processing device 10 as described in
[0130] Further, whereas
[0131] Further still, the impeller 108 of
[0132] A still further embodiment is schematically shown in
[0133] Upon completing the morselization of TPs within a processing device 910, the TPs are released in solution through a drain 939 from the bottom 920 of container 912. The drain 939 is preferably located about a central axis A of the processing device 910 or otherwise appropriately located on the bottom 920 of the container 912, so as to fluidly communicate into a central chamber 972 of the centrifugal isolation device 919.
[0134] One or more individual collection chambers 973 protrude radially from the central chamber 972, each collection chamber having a distal outlet orifice 974. The distal outlet orifice 974 has a standard threaded female Luer engagement for interchangeable attachment of a standard Luer cap 975 or a standard Luer tipped syringe (not shown).
[0135] The central chamber 972 and radially extending collection chambers 973 may be integrally formed as a hollow injection blow molded component, or produced as an assembly of injection molded components, or a combination, for example with injection molded Luer fittings affixed onto an injection blow molded unibody core.
[0136] The centrifugal isolation device 919 is configured to rotate at a high speed, for example up to 300 Gs, on precision radial type ball bearings (not shown), about an axis that is preferably coincident to or axially aligned with axis A of the processing device 910. The spinning isolation device 919 is preferably encased within a protective shroud 976. Should the Processing device 910 and the centrifugal isolation device 919 rotate about the same axis, the ball-bearing's inner shaft diameter may be sized sufficiently large as to enable independent rotation of the centrifugal isolation device 919 relative to rotation of the impeller 908 within the processing device 910.
[0137] Upon being centrifugally spun for only a few minutes, the solution suspended TP's will separate and become compacted within the radially extending collection chambers. The Luer caps 975 on the distally extending female Luer connectors 974 are then unthreaded and exchanged with appropriately sized standard syringes. Upon then drawing the compacted TPs into the syringes, the filled syringes are disengaged from the isolation device 919 and a selected Luer fitting applicator tip (for example as previously described in
Morselized Particulates
[0138] A solution of suspended TPs or specifically FTSGPs or other tissues particles as described herein, may be mixed in combination with other FDA approved additives, for example handling (i.e. in saline, a buffer solution, or BioLife Solution®, or other cell nurturing/preservation solutions, etc.). The mixture may be created within the processing device 10, using the vortex circulation to achieve a heterogenous mixture of morsels comprised of naturally connected cellular and extracellular matrix material. Alternatively, some suspensions/dispersions of TPs may be homogeneous. Whether the dispersion or emulsion produced is homogeneous or heterogeneous may depend on a number of factors, including without limitation, the type of tissue(s), the medium it is suspended in, the speed and temperature of the process, among other factors. An important advantage of the method of creating the TPs suspension/dispersion of the invention, as well as the resultant suspension/disperisons per se, relates to the high cellular viability during and immediately after processing to achieve the morselization. This ability to morselized while maintaining such high cellular viability, as described herein, is unique to the present invention and not achieved by prior methods. The methods described herein produce suspensions or dispersions which contain TPs having at least 50% viability immediately after processing, which is generally in real time at the bedside of the patient; or at least 60% viability immediately after processing; or at least 70% viability immediately after processing; or at least 80% viability immediately after processing; or at least 85% viability immediately after processing; or at least 90% viability immediately after processing; or at least 92% viability immediately after processing; or at least 94% viability immediately after processing; or at least 96% viability immediately after processing; or at least 97% viability immediately after processing; or at least 98% viability immediately after processing; or at least 99% viability immediately after processing. Generally, the processing may take about 1 hour, but desirably less than 1 hour, for example, 45 minutes or less, 40 minutes or less, 30 minutes or less, 20 minutes or less, or 10 minutes or less.
[0139] The TPs may also be centrifuged to vary the density, viscosity and consistency of the tissue particles, as may be desirable for alternative surgical applications. Modulating the centrifuge speed and duration of centrifuging enables the customization of the resultant output tissue particle form, for example the consistency and density may present as a solution, or a paste, or a cream. Desirably, the resultant output (Id.) flowable and/or easily applied by spreading. The resultant output may further be presented, for example, as compacted tissue form or may be further spun to present as compacted cellular matter.
[0140] The TPs as defined herein may be most efficiently delivered from a variety of fluid dispensing devices, most notably syringes, which are familiar and useful to easily meter controlled volumes. The targeted particulate sizes will pass freely as a fluid composition through the lumen of standard Luer connectors. Tips may be interchangeably attached onto an applicator, for example, with a standard Luer thread. A variety of interchangeable applicator tips may be included within a dispensing kit for selection as most appropriate for a specific application at the option of the surgeon for a given procedure. In a cream, paste or fluid form, the TP, for example FTSGPs, may be dispensed from a syringe through various selected tip types of applicator tips. A tip may have a narrow/long fanned outlet orifice to spread over a large area. Such a fanned tip may be comprised of a flexible low durometer silicone or thermoplastic elastomer and may have a thin flexible edge, so as to be useful to gently and evenly spread the TPs over large and/or irregular wound surfaces, for example burns.
[0141] In a dense form, the TP of the invention may be spread or applied over areas or into crevices, for example with a spatula. In a dense form, the TPs, for example Cartilage Particles (CPs), may be used as a filler, for example for cartilage defects. As such the TPs, such as CPs or other tissues particles as defined herein, may be mixed with fibrin glue, autologous Platelet Rich Plasma, growth factors or other FDA approvable materials, for example as a binder. Cartilage or organ TP's may also be delivered through an endoscopic syringe attachment.
[0142] In a fluid a cream or solution form partial thickness dermal skin graft particles may alternatively be dispensed from a syringe, through a flexible cannula or a needle, for subdermal applications, for example, to fill cosmetic defects. For delivering the various TPs as described the lumen may range, for example, from 22 to 18 gauge, or most notably 22 or 21 gauge.
[0143] In a highly soluble form the TPs, which in such a case may be of the smaller variety, as described herein, may be sprayed over large areas. In the case of TPs for use on burns or open wounds, a non-adherent surgical wound dressing, may be used to prevent the applied TPs from migrating while keeping the wound site moist and protected from infection. Such commercially available dressings include, for example, commercially available Drawtex, Sofsorb, Kalginate, or Aquasorb dressings.
System Methodology
[0144] A system of devices is described to perform a process in a methodical sequence. With reference additionally to
[0145] A processor device may be used in conjunction with various types of isolation devices. For example, an isolation device may take the form of a device including a filter tube through which solution flows to isolate tissue particles as described in
[0146] A processor device may also be used in conjunction with various types of applicator devices. For example, an applicator device may be a standard syringe; or an isolation device may additionally be deployed for use as an applicator as described in
FTSG Process Verification Studies
[0147] Full Thickness Skin Grafts (FTSGs) harvested from a human abdominoplasty were prepared in accordance with the methods disclosed herein and using the apparatus and systems disclosed herein.
[0148] Harvested sample FTSGs of various noted sizes were each separately and individually placed into fabricated experimental test apparatuses modeled as generally described in
[0149] Morselized tissue samples were quantitatively assessed to determine cell viability. Processed FTSGPs suspended in solution were transferred using a syringe into 0.5 ml aliquots. The aliquots were maintained chilled in a container of chipped ice. The samples were spun down in a centrifuge at 700 RPM for five minutes followed by removing the supernatant. Quantitative cell viability analysis was performed using standard trypan blue test protocols to stain and count living cells versus purple ruptured dead cells. A table included as
[0150] Additional MTT tests yielded similar quantitative results to consistently confirm data reliability. Morselized tissue particles were also qualitatively assessed. Resultant morselized tissue particles, suspended in solution, were drawn from the processor through a cannula into a syringe and expelled into a petri dish to form a shallow pool or puddle aside a metric scale. Photos of the morselized FTSGPs are shown, herein, each photo identified by test sample numbers, to visually and qualitatively document relative morsel sizes and particle appearance. As evident in the images, tissue particle sizes are relatively consistent within each sample. Maximum particle sizes became progressively smaller with longer total duration of processing time.
[0151] In exemplary morselization studies, ten portions of full tissue skin grafts (FTSGs), each approximately 12 mm×6 mm×4 mm thick were morselized in a processor without baffles, containing 35 ml of buffer solution with the blades rotating at approximately 550 RPM.
[0152] In a next exemplary morselization study, still using the same patient tissue, the processing chamber included three baffles and four (versus 10) portions of FTSGs. The sample was again processed with 35 ml buffer and 550 RPM. As shown in
[0153] In other studies, not included here, similarly morselized FTSGPs have been demonstrated to be injectable through 22 gauge needles. The term injectable as used herein is meant to include dispensing through a syringe and is not intended to be limited to being injected only into the body, but also includes dispensing onto the body, such as onto a wound.
[0154] In a next exemplary morselization study (test 4a)—again using the same patient tissue and processing device and process parameters—multiple larger portions of tissue, measuring approximately 2 cm×3 cm were inserted into the processor and morselized for 4 minutes.
[0155]
[0156]
[0157] A similarly sized (slightly larger) single portion of FTSG, measuring approximately 2.5 cm×4.5 cm was morselized for 4 minutes before taking the photo for
[0158] The tabled data in
[0159] FTSGPs shown in
Articular Cartilage Process Verification Studies
[0160] Articular cartilage was harvested from the peripheral edges of a bovine knee condyle using a 2.5 mm ring curette and then morselized in accordance with the methods disclosed herein and using the apparatus and systems disclosed herein.
[0161] The harvested cartilage portions, shown in
[0162] The resultant cartilage morsels are shown in
[0163] Further details of the present invention are shown and described hereinbelow with respect to
[0164] It is contemplated that the present invention meets a significant unmet need. Full thickness skin grafts are the gold standard for chronic wounds and burns, but are rarely used because dermatomas create donor sites that do not heal and the procedure must typically be done in an operating room.
[0165] The present invention can generate a full thickness skin graft rapidly without leaving a conventional donor site to heal.
[0166] The present invention can also be customized to be applied to fit wound anatomy and can be done as an office procedure. The resulting process of the present invention and the grafts produced thereby are fast to process, are minimally invasive, antiseptic, provide superior viability and are cost effective solutions for wound healing. The system, equipment and process of the present invention can be conducted at bedside, including preparation of the morselized TPs and formation of a fluid having a pH to help sustain the tissues, and dispensing of the TPs onto/into the area intended to be treated, which may be a wound, a cosmetic or plastic surgery area, an internal organ area and the like.
[0167] As shown in
[0168] Referring to
[0169] Turning now to
[0170]
[0171]
[0172]
[0173]
[0174]
[0175] The above-presented description and figures are intended by way of example only, and are not intended to limit the present invention in any way except as set forth in the following claims. It is particularly noted that persons skilled in the art can readily combine various technical aspects of the elements of the various exemplary embodiments described above in numerous other ways, all of which are considered to be within the scope of the invention.