METHODS AND COMPOSITIONS FOR DELIVERING COMPACT LYOPHILIZED AGENTS FOR DISSOLVING IN A CLOSED SYSTEM

Abstract

The invention relates to packaged lyophilized agents. In particular, the present invention relates to compact lyophilized agents that are packaged in flexible containers, and systems for their manufacture and use.

Claims

1. A system comprising at least one compact lyophilized agent housed within a flexible container.

2. The system of claim 1, wherein the system comprises one compact lyophilized agent.

3. The system of claim 1, wherein the system comprises two or more compact lyophilized agents.

4. The system of any one of claims 1-3, wherein the at least one compact lyophilized agent comprises a protein or a small molecule.

5. The system of claim 4, wherein the at least one agent comprises a protein selected from Flt-3 ligand, TPO, G-CSF, GM-CSF, IFN-gamma, IL-1 beta, IL-2, IL-3, IL-4, IL-6, IL-7, IL-10, IL-12, IL-15, IL-18, IL-21, M-CSF, Activin A, BMP-4, EGF, FGF basic, FGF-3, FGF-10, IGF-1, KGF/FGF-7, LIF, Noggin, PDGF-BB, R-Spondin 1 SCF/c-kit, Sonic Hedgehog, TGF-beta 1, VEGF 165, and Mouse LIF.

6. The system of any one of claims 1-5, wherein the at least one compact lyophilized agent further comprises a colorant.

7. The system of any one of claims 3-6, wherein each of two or more compact lyophilized agents comprises a colorant.

8. The system of claim 7, wherein two or more compact lyophilized agents comprise distinct colorants.

9. The system of claim 8, wherein compact lyophilized agents comprising distinct colorants comprise different amounts of at least one agent.

10. The system of claim 8, wherein compact lyophilized agents comprising distinct colorants comprise at least one different agent.

11. The system of any one of claims 1-10, wherein the flexible container is sterile.

12. The system of any one of claims 1-11, wherein the flexible container comprises a means for addition of a reconstitution fluid to the flexible container.

13. The system of claim 12, wherein the at least one compact lyophilized agent dissolves within one minute of the reconstitution fluid being added to the system.

14. The system of claim 12 or claim 13, wherein the system further comprises a means for delivering the reconstituted lyophilized agent from the flexible container to a second system.

15. The system of claim 14, wherein the second system is a cell culture system, a bioreactor, a fermenter, or a subject.

16. The system of claim 15, wherein the subject is a mammal.

17. The system of claim 16, wherein the subject is a human.

18. An aseptic closed system comprising: i) a flexible container that houses at least one compact lyophilized agent; and ii) a cell culture system containing a culture medium, wherein the flexible container is connected to the cell culture system at a fluid connection.

19. The system of claim 18, wherein the cell culture system comprises a bioreactor or fermenter.

20. The system of claim 18 or claim 19, wherein the fluid connection comprises weldable tubing.

21. A method, comprising: i) delivering at least one compact lyophilized agent into flexible container; and ii) sealing the flexible container, wherein the flexible container comprises a weldable bag comprising at least one port, and wherein the sealing comprises welding the weldable bag.

22. The method of claim 21, wherein the weldable bag is gas-impermeable.

23. A method, comprising: i) delivering reconstitution fluid into a flexible container that houses at least one compact lyophilized agent to form reconstituted lyophilized agent; and ii) delivering reconstituted lyophilized agent from the flexible container to a second system.

24. The method of claim 23, wherein the second system is a cell culture system, a bioreactor, a fermenter, or a subject.

25. The method of claim 23, wherein the cell culture system comprises a bag comprising a culture medium.

26. The method of claim 23, wherein the flexible container and the second system are connected at a fluid connection.

27. The method of claim 26, wherein the fluid connection comprises a Luer connector.

28. The method of claim 26 or claim 27, wherein the fluid connection comprises tubing.

29. The method of claim 28, wherein the tubing comprises a welded connection.

30. A method, comprising: i) aseptically delivering reconstitution medium into a flexible container that houses at least one compact lyophilized agent to form reconstituted lyophilized agent; and ii) aseptically delivering a cell to the reconstituted medium in the flexible container.

31. The method of claim 30, further comprising incubating the cell in the reconstituted medium.

Description

DESCRIPTION OF THE DRAWINGS

[0033] These and other features, aspects, and advantages of the present technology may become better understood by reference to the following drawings:

[0034] FIG. 1A is a picture showing an embodiment of the flexible container described herein.

[0035] FIG. 1B is a schematic diagram of an embodiment of a flexible container described herein.

[0036] FIG. 2 is a schematic diagram showing various embodiments of the packaged compact lyophilized agents described herein. The compact lyophilized agent may be stored in a sterile, flexible container (e.g., a bag). A container may hold one type of compact lyophilized agent (left panel, showing circles representing three different proteins (P #1, P #2, and P #3) in separate flexible containers). Alternatively, a flexible container may hold multiple, distinct compact lyophilized agents (right panel).

[0037] FIG. 3A-3B show RP-HPLC results after dissolving a compact lyophilized dot of recombinant human IL-7 (rhIL-7) dot in reconstitution buffer. Reverse phase 280 nm absorbance traces of rhIL-7 at times t=0 and t=30 minutes post reconstitution are shown. 50 μL of sample at 0.1 mg/mL were loaded to Agilent C3 Reverse Phase and separated using a water/TFA to acetonitrile/TFA gradient. Samples tested are rhIL-7 ProDots® compact lyophilized IL-7 deriving from Bulk Lot GAAS02 immediately upon reconstitution (FIG. 3A) and 30 minutes afterwards (FIG. 3B).

[0038] FIG. 4A-4B show mass spectrometry results after dissolving a compact lyophilized dot of recombinant human IL-7 dot in reconstitution buffer. 50 μL of sample at 0.1 mg/mL were loaded to Agilent C3 Reverse Phase and separated using a water/TFA to acetonitrile/TFA gradient. Samples tested are bagged rhIL-7 ProDots® deriving from Bulk Lot GAAS02 immediately upon reconstitution (FIG. 4A) and 30 minutes afterwards (FIG. 4B).

DETAILED DESCRIPTION OF THE INVENTION

[0039] The technology relates to packaged lyophilized agents. In particular, the technology relates to compact lyophilized agents that are packaged in flexible containers.

[0040] The systems described herein are advantageous in that the systems provide a compact lyophilized agent in a ready-to-use flexible storage container that allows for rapid reconstitution of the agent and direct transfer to the second system without the need for manual reconstitution and aliquoting steps. Maintaining sterility is critical to many systems, including cell culture systems and therapeutic systems and accordingly any open, manipulation increases the risk of contamination. The systems provided herein eliminate open manipulation and lower the chance for contamination.

[0041] In some embodiments, provided herein are systems comprising at least one compact lyophilized agent housed within a flexible container. In preferred embodiments, essentially all lyophilized agent housed within the flexible container is within one or more units of the at least one compact lyophilized agent. In some embodiments, the system comprises one compact lyophilized agent. In other embodiments, the system comprises two or more compact lyophilized agents. For example, the system may comprise two compact lyophilized agents, three compact lyophilized agents, four compact lyophilized agents, five compact lyophilized agents, six compact lyophilized agents, seven compact lyophilized agents, eight compact lyophilized agents, nine compact lyophilized agents, or ten or more compact lyophilized agents. The number and selection of the compact lyophilized agents will depend on the intended use of the system (e.g., for cell culture methods, therapeutic methods, etc.).

[0042] The at least one compact lyophilized agent may be any suitable agent. For example, the agent may comprise a suitable protein or small molecule. In some embodiments, the agent comprises a protein. In other embodiments, the agent comprises a small molecule. The specific agent will depend on the intended use of the system. For example, for systems intended for use in cell culture methods, any suitable protein and/or small molecule for cell culture may be selected. Exemplary proteins for use in cell culture include, but are not limited to, Flt-3 Ligand, G-CSF, GM-CSF, TPO, IFN-gamma, IL-1 beta, IL-2, IL-3, IL-4, IL-6, IL-7 IL-10, IL-12, IL-15, IL-18, IL-21, M-CSF, Activin A, BMP-4, EGF, FGF basic, FGF-3, FGF-10, IGF-1, KGF/FGF-7, LIF, Noggin, PDGF-BB, R-Spondin 1 SCF/c-kit, Sonic Hedgehog, TGF-beta 1, VEGF 165, and Mouse LIF. As another example, for systems intended for use in therapeutics, the agent may comprise any suitable protein and/or small molecule for treatment of a disease or condition in a subject. In some embodiments, the at least one compact lyophilized agent is a ProDots® protein.

[0043] The compact lyophilized agent may comprise any suitable amount of the agent. Suitable amounts will depend on, for example, the intended use of the system. In some embodiments, the compact lyophilized agent may comprise 1 ng to 100 g of the agent. For example, the compact lyophilized agent may comprise 1 ng, 5 ng, 10 ng, 20 ng, 30 ng, 40 ng, 50 ng, 60 ng, 70 ng, 80 ng, 90 to 999 ng; or any amount therebetween; 1 μg, 5 μg, 10 μg, 20 μg, 30 μg, 40 μg, 50 μg, 60 μg, 70 μg, 80 μg, 90 to 999 μg, or any amount therebetween; 1 mg, 5 mg, 10 mg, 20 mg, 30 mg, 40 mg, 50 mg, 60 mg, 70 mg, 80 mg, 90 mg, 100 mg, 150 mg, 200 mg, 250 mg, 300 mg, 350 mg, 400 mg, 450 mg, 500 mg, 550 mg, 600 mg, 650 mg, 700 mg, 750 mg, 800 mg, 900 mg, 1 g, 10 g, 20 g, 30 g, 40 g, 50 g, 60 g, 70 g, 80 g, 90 g, or 100 g of the agent. The above examples are not intended to be limiting, any suitable defined amount of the lyophilized agent may be used.

[0044] In some embodiments, the at least one compact lyophilized agent further comprises one or more carriers or excipients. The terms “carrier” and “excipient” are used interchangeably herein, and refer to agents that facilitate any aspect of working with compact lyophilized agents, e.g., production, storage, handling, packaging, transport, stabilizing, solubility, bioavailability, etc. In some embodiments, a carrier is used to provide additional bulk or mass, such that a desired small amount of a principal agent, e.g., a protein, can be formed into a compact lyophilized form having particular desired properties, e.g., size, weight, shape, porosity, hardness, color, for a particular intended use. Such carriers may be added to the principal agent prior to lyophilization and formation of the compact form. Suitable carriers include, for example, BSA, HSA, sucrose, lactose, trehalose, mannitol, surfactants, phospholipids, and the like. In some embodiments, the compact lyophilized agent does not comprise any carriers (e.g., the compact lyophilized agent consists of pure lyophilized protein).

[0045] In some embodiments, the at least one compact lyophilized agent further comprises an indicator, e.g., a colorant. See, e.g., Allam, et al., International Journal of Pharmacy and Pharmaceutical Sciences Vol 3, Suppl 3, 201, which is incorporated herein by reference in its entirety. In preferred embodiments, the indicator is colored pigment or dye. A colorant may be natural (e.g., a plant-derived colorant, such as an anthocyanidin) or may be synthetic. A colorant may, for example, be used to indicate the type and/or quantity of agent housed within the system. In some embodiments, a colorant may be used to indicate which specific protein and/or small molecule is present. Any suitable color of colorant may be used, including red, orange, yellow, green, blue, purple, black, gray, etc. In some embodiments, a colorant may be detectable by detecting fluorescence. In some embodiments, the color of the colorant may be selected to allow for easy visual confirmation that the appropriate number and/or type of compact lyophilized agent(s) are present in the flexible container.

[0046] In some embodiments, the system comprises two or more compact lyophilized agents and each agent comprises a colorant. Any suitable colorant or combination of colorants may be used. For example, the system may comprise two or more compact lyophilized agents that comprise the same protein and/or small molecule. In this instance, each of the two or more agents may further comprise the same colorant (e.g. blue, red, green, yellow, purple, black, etc.). Alternatively, the system may comprise two or more compact lyophilized agents, wherein at least one of the compact lyophilized agents is distinct from another agent (e.g., one agent comprises protein X, the other agent comprises protein Y). In such embodiments, the agent comprising protein X may comprise a first colorant and the agent comprising protein Y may comprise a second colorant. Accordingly, the user is able to visually confirm that the correct number and types of compact lyophilized agents are present in the system. Similarly, in some embodiments, one compact lyophilized agent comprises a first amount of protein X and the other compact lyophilized agent comprises a different amount of protein X, and the agent comprising the first amount of protein X may comprise a first colorant and the agent comprising the second amount of protein X may comprise a second colorant. Accordingly, the user is able to visually confirm that a correct total amount of protein X present in the system by confirming the correct numbers of each color of compact lyophilized agents are present in the system.

[0047] The at least one compact lyophilized agent may be any suitable size and shape. In some embodiments, the compact lyophilized agent may be a spherical shape. In some embodiments, the compact lyophilized agent may be a size that can visualized without the use of a microscope. For example, the compact lyophilized agent may be at least 1 mm in diameter. For example, the compact lyophilized agent may be a spherical shape of about 1 mm to about 10 cm in diameter. For example, the compact lyophilized agent may be a spherical shape of about 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 2 cm, 3 cm, 4 cm, 5 cm, 6 cm, 7 cm, 8 cm, 9 cm, or 10 cm in diameter. In some embodiments, the compact lyophilized agent may be larger than 10 cm in diameter.

[0048] In accordance with any of the embodiments described herein, the at least one compact lyophilized agent is housed within a flexible container. The compact lyophilized agent may be housed within the flexible container without being adhered to an interior surface of the flexible container. For example, the compact lyophilized agent may be moveable within the flexible container. Allowing the compact lyophilized agent to be movable within the flexible container may enable shipping or transporting of the system with minimal risk of damage to the compact lyophilized agent, such as minimal risk of breaking the compact lyophilized reagent.

[0049] The flexible container may be any suitable size or shape. In some embodiments, the flexible container is a bag. In some embodiments, the flexible container is a weldable bag. In some embodiments, the flexible container may be sterile. Sterility may be achieved by any suitable method as known in the art, including dry heat, autoclaving (e.g. steam sterilization), ethylene oxide, irradiation, gamma-ray, e-beam, supercritical CO2 and the like.

[0050] The flexible containers described herein may comprise any suitable material or combination of suitable materials. Suitable materials include, for example, polyethylene, ethylene vinyl alcohol, silicone, polycarbonate, FEP (Fluoroethyl polymer); EVA (Ethylene vinyl acetate), ULDPE (ultra low-density polyethylene), and the like. The flexible container may comprise one layer or multiple layers. For example, the flexible container may be a single layer bag or a multi-layer bag. In particular embodiments, the flexible container may comprise multilayer films including one or more of polyethylene, polyester, ethylene vinyl alcohol EVOH, and ultra low-density polyethylene.

[0051] In some embodiments, the flexible container may be gas permeable. In other embodiments, the flexible container may be gas impermeable. In some embodiments, a flexible container may comprise gas-permeable portions and gas impermeable portions. For example, in some embodiments, a compact lyophilized agent may be packaged within a gas-impermeable area of or within a flexible container, such that the agent can be manipulated into a gas-permeable portion of the container. In some embodiments, the agent is dissolved or suspended before manipulation into a gas-permeable portion of a flexible container, and in some embodiments, the agent is manipulated into a gas-permeable portion of the flexible container while still in a lyophilized form.

[0052] In some embodiments, the flexible container may be light blocking. For example, in embodiments, wherein the agent is photo labile, the flexible container may be partially or completely light blocking to prevent degradation of the agent.

[0053] In some embodiments, the flexible container may be sealed within a suitable packaging. For example, the system may be sealed within a vacuum-sealed pouch, such as an aluminum pouch. In some embodiments, the packaging may include a desiccant. In some embodiments, the packaging may be light blocking. In particular embodiments, the flexible container may be sealed within a vacuum-sealed foil pouch. In such embodiments, the user may open the packaging prior to use of the system. In particular embodiments, the user may open the packaging and clean and/or sterilize the exterior of the flexible container prior to use. For example, the user may open the packaging and sterilize the exterior of the flexible container with a suitable solution (e.g. isopropanol solution) prior to use.

[0054] In some embodiments, the flexible container further comprises a means for addition of a reconstitution fluid to the flexible container to allow for dissolution of the at least one compact lyophilized agent housed within the flexible container. For example, the flexible container may further comprise a port for tubing (e.g. weldable tubing). In some embodiments, the port allows for two-way flow of liquid (e.g., flow of liquid into and out of the flexible container). In some embodiments, tubing can be connected to the port of the flexible container by a suitable method to allow for addition of a reconstitution buffer to the tubing and subsequent flow from the tubing into the flexible container and/or flow from the flexible container back into the tubing. As another example, the flexible container may further comprise a port that allows for the direct addition of reconstitution fluid to the flexible container through a syringe, pipette, needle, and the like. In accordance with any of these embodiments the port may be sealed when not in use by any suitable means, including caps, stoppers, lids, etc. Alternatively, the flexible container may comprise a port that is able to be punctured (e.g. by a needle) to allow for direct addition of the reconstitution fluid to the flexible container through a syringe.

[0055] In some embodiments, the flexible container further comprises a means for delivering the reconstituted lyophilized agent from the flexible container to a second system. In some embodiments, the second system may be a closed system. The closed system may be any system in which the reconstituted agent is not exposed to the ambient environment. For example, the closed system may be a closed cell culture system. In some embodiments, the second system may be a functionally closed system, such as a functionally closed cell culture system. In some embodiments, the flexible container may further comprise a means for delivering the reconstituted lyophilized agent from the flexible container to the closed or functionally closed cell culture system. For example, the flexible container may further comprise a port for weldable tubing that may be connected to a component of the cell culture system to allow for transfer of the reconstituted lyophilized agent from the flexible container to the component of the cell culture system. Suitable components of the closed cell culture system include, for example, flasks, vials, tubes, plates, dishes, bags, cell culture media, tubing, and the like. In some embodiments, the second system may be a bioreactor. In some embodiments, the second system may be a fermenter.

[0056] In some embodiments, the second system comprises a suitable container holding cell culture media. For example, the second system may be a culture media bag. In such embodiments, the flexible container may comprise a port for weldable tubing. Accordingly, the flexible container may be connected to the culture media bag by the weldable tubing. The user may manually manipulate the culture medium through this connection to the flexible container to solubilize the compact lyophilized agent. The user may subsequently manually manipulate the reconstituted agent back to the culture medium bag through this connection. The fluid manipulation between the flexible container and the second system may be repeated multiple times as necessary. For example, the fluid manipulation may be repeated 4-5 times to ensure that all of the dissolved agent (e.g., protein) is moved to the second container (e.g., the culture media bag). The fluid in the culture media bag may then be transferred via sterile tubing to the desired component of the cell culture system. The fluid manipulation may be performed manually, e.g., by a subject or worker, or by use of an automated system. For example, an automated system may comprise a peristaltic, positive, or negative pressure pump flowing liquid in either a laminar or turbulent manner.

[0057] In some embodiments, the second system may be a subject. In some embodiments, the subject may be a mammal. For example, the subject may be a human. The flexible container may further comprise a means for delivering the reconstituted lyophilized agent from the flexible container to the subject. For example, the flexible container may further comprise a port for tubing (e.g., weldable tubing), that can be connected to the flexible container. The tubing may be connected to a needle or a syringe which can be placed into the subject (e.g., parenterally) to allow for transfer of the reconstituted lyophilized agent from the flexible container through the tubing and into the subject. For example, the needle may be placed into the subject intravenously, subcutaneously, intramuscularly, and the like. In some embodiments the tubing may be configured for fluid connection to a system for delivering fluids to a subject, e.g., an intravenous (I.V.) system. For example, in some embodiments, the tubing comprises a connector, e.g., a Luer connector, for connection to an I.V. system that is connected to the subject, such that reconstituted lyophilized agent is delivered to the subject via the I.V. system.

[0058] The systems described herein display several advantages over the art. In some aspects, the systems described herein are advantageous in that they allow for rapid dissolution of the compact lyophilized agent housed within the flexible container and are immediately ready for use. In some embodiments, the at least one compact lyophilized agent dissolves within one minute of the reconstitution buffer being added to the system. For example, the at least one compact lyophilized agent may dissolve in less than 60 seconds, less than 55 seconds, less than 50 seconds, less than 45 seconds, less than 40 seconds, less than 35 seconds, less than 30 seconds, less than 25 seconds, less than 20 seconds, less than 15 seconds, less than 10 seconds, less than 5 seconds, less than 2.5 seconds, or less than 1 second after addition of the reconstitution buffer to the flexible container.

[0059] In other aspects, the systems described herein are advantageous in that the compact lyophilized agent(s) display minimal adherence to the flexible container. This is in contrast to traditional lyophilized agents, e.g., a lyophilized cake formed in a vial, which may be completely or partially adhered to the vial in which it is packaged. Accordingly, the systems described herein allow for dissolution of the compact lyophilized agent and transfer of the reconstituted agent to the desired system without loss of the agent (e.g., without loss of protein or small molecule). In preferred embodiments, compact lyophilized agents of the technology can be moved from container to container, or moved within a container by use of external forces, e.g., gravity. In preferred embodiments, compact lyophilized agents of the technology are droppable (e.g., can be placed in packaging by dropping into the package) and rollable (e.g., will roll on a sloped surface, for example into or out of a flexible package, or between different points within a flexible package, by force of gravity).

EXPERIMENTAL EXAMPLES

Example 1

[0060] Input Materials: [0061] Lyophilized ProDots® containing rhIL-7 GMP Bulk Lot GAAS02 (5 μg per ProDot) [0062] Weldable, sterile bags with appropriate fittings [0063] Weldable foil pouch for final storage (tear-open with resealable Zipper Tamper Evident (ZTE) ZipSeal™ bags)

[0064] Material Preparation:

[0065] ProDots® of rhIL-7 GMP from Bulk Lot GAAS02 were formulated, lyophilized, and packaged into weldable bags for dissolution and functional testing.

[0066] Test Sample generated for analysis: [0067] ProDots (rhIL-7) in Weldable Bags within Vacuum-sealed Foil Pouches [0068] 1×5 μg ProDot per bag—OR— [0069] 5×5 μg ProDot per bag

[0070] Experimental Design:

[0071] Materials were removed from the recommended storage condition, allowed to equilibrate to room temperature. Any external packaging (e.g., foil pouch or aluminum crimp seals) was removed and the product was reconstituted by adding sufficient volume of Dulbecco's Phosphate-Buffered Saline (PBS) to yield a final concentration of 100 μg/mL.

[0072] Analytical Testing by RP-HPLC and Mass Spectrometry:

[0073] ProDots® dissolve within seconds to <1 minute of reconstitution buffer being added. In contrast, traditional lyophilized products, e.g., in the form of a cake at the bottom of a glass vial (made from liquid lyophilized in the vial; see, e.g., 207-GMP-025 at www<dot>mdsystems<dot>com/products/good-manufacturing-practices-gmp-grade-proteins), are designed to fully dissolve within 30 minutes after reconstitution buffer is added.

[0074] Accordingly, analytical testing by reverse phase high performance liquid chromatography (RP-HPLC) and mass spectrometry was done at two time-points after reconstitution buffer was added: <1 minute (termed t=0 min) and 30 minutes (t=30 min). Due to mass requirements for testing, all containers tested (ProDots® in welded bags, and traditional lyophilized protein in vials) contained 25 μg total product.

TABLE-US-00001 TABLE 1 Peak recovery of 5 ug loads in C3 reverse phase of Recombinant Human IL-7 after reconstitution to 0.1 mg/mL. Samples were tested at t = 0 and t = 30 minutes. Peak Sample Retention Peak Area Sample Type (min) (280 nm) Time rhIL-7 GAAS02 In Bag 8.949 89.318 0 min ProDots ® rhIL-7 GAAS02 In Bag 8.947 88.248 30 min ProDots ®

Summary of RP-HPLC Results:

[0075] As shown in FIG. 3A-3B and Table 1, no difference in reconstitution between t=0 min and t=30 minutes was observed for the ProDots® sample. This suggests that reconstitution is very fast and that no further material is dissolved after 30 additional minutes of incubation with reconstitution buffer.

Summary of Mass Spectrometry results:

[0076] As shown in FIG. 4A-4B, all samples showed nearly indistinguishable spectra between ProDots® in bags at the two timepoints. The expected mass under these testing conditions is 17500.930 Da, and all materials tested matched this well for the major peak and was well within the accuracy of the Thermo Scientific™ Q Exactive™ HF instrument. Accordingly, the bioactive ingredient, rhIL-7, is unaltered based on any treatment or intermediate preparation. Moreover, this methodology allows for clear confirmation of the identity of the bioactive ingredient in a ProDots®. Accordingly, this methodology allows for distinguishing between different bioactive agents, such as between (e.g., rhIL-7 & rhIL-2).

[0077] All literature and similar materials cited in this application, including but not limited to, patents, patent applications, articles, books, treatises, and internet web pages are expressly incorporated by reference in their entirety for any purpose. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of ordinary skill in the art to which the various embodiments described herein belongs. When definitions of terms in incorporated references appear to differ from the definitions provided in the present teachings, the definition provided in the present teachings shall control.

[0078] Various modifications and variations of the described compositions, methods, and uses of the technology will be apparent to those skilled in the art without departing from the scope and spirit of the technology as described. Although the technology has been described in connection with specific exemplary embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention that are obvious to those skilled in pharmacology, biochemistry, medical science, or related fields are intended to be within the scope of the following claims.