Gels for encapsulation of biological materials

• US 7,413,781 B2
• Filed: 12/22/2006
• Issued: 08/19/2008
• Est. Priority Date: 10/15/1990
• Status: Expired due to Fees

• Current Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Original Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Inventors: Desai, Neil P., Pathak, Chandrashekhar P., Sawhney, Amarpreet S., Hossainy, Syed F. A., Hubbell, Jeffrey A.
• Primary Examiner(s): Berman; Susan W
• Application Number:
  US11/644,606
• Publication Number:
  US 20070100015A1
• Time in Patent Office: 606 Days
• Field of Search: 522/182, 522/85, 522/87, 522/88, 427/512, 427/517, 424/491, 424/492, 424/493, 424/494, 424/496
• US Class Current: 427/512
• CPC Class Codes: A61K 2035/128 capsules, e.g. microcapsules
• CPC Class Codes: A61K 35/30 Nerves; Brain; Eyes; Corneal cells; Cerebrospinal fluid; Neuronal stem cells; Neuronal precursor cells; Glial cells; Oligodendrocytes; Schwann cells; Astroglia; Astrocytes; Choroid plexus; Spinal cord tissue
• CPC Class Codes: A61K 35/39 Pancreas; Islets of Langerhans Langerhans cells of epidermis A61K35/36
• CPC Class Codes: A61K 38/42 Haemoglobins; Myoglobins
• CPC Class Codes: A61K 38/44 Oxidoreductases (1)
• CPC Class Codes: A61K 47/645 Polycationic or polyanionic oligopeptides, polypeptides or polyamino acids, e.g. polylysine, polyarginine, polyglutamic acid or peptide TAT
• CPC Class Codes: A61K 47/6925 the form being a microcapsule, nanocapsule, microbubble or nanobubble
• CPC Class Codes: A61K 9/1635 obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyvinyl pyrrolidone, poly(meth)acrylates
• CPC Class Codes: A61K 9/1647 Polyesters, e.g. poly(lactide-co-glycolide)
• CPC Class Codes: A61K 9/5031 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyethylene glycol, poly(lactide-co-glycolide)
• CPC Class Codes: A61K 9/5073 having two or more different coatings optionally including drug-containing subcoatings
• CPC Class Codes: A61L 24/0031 Hydrogels or hydrocolloids
• CPC Class Codes: A61L 24/0042 Materials resorbable by the body
• CPC Class Codes: A61L 24/046 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds A61L24/043 takes precedence
• CPC Class Codes: A61L 26/0019 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 27/34 Macromolecular materials
• CPC Class Codes: A61L 27/38 containing added animal cells organs or tissue containing native cells A61L27/36
• CPC Class Codes: A61L 27/52 Hydrogels or hydrocolloids
• CPC Class Codes: A61L 29/085 Macromolecular materials
• CPC Class Codes: A61L 31/10 Macromolecular materials
• CPC Class Codes: A61L 31/145 : Hydrogels or hydrocolloids
• CPC Class Codes: A61L 31/148 : Materials at least partially resorbable by the body
• CPC Class Codes: C08F 290/00 : Macromolecular compounds obtained by polymerising monomers on to polymers modified by introduction of aliphatic unsaturated end or side groups
• CPC Class Codes: C08F 290/02 : on to polymers modified by introduction of unsaturated end groups
• CPC Class Codes: C08F 290/06 : Polymers provided for in subclass C08G
• CPC Class Codes: C08F 290/062 : Polyethers
• CPC Class Codes: C08F 290/14 : Polymers provided for in subclass C08G
• CPC Class Codes: C08F 291/00 : Macromolecular compounds obtained by polymerising monomers on to macromolecular compounds according to more than one of the groups C08F251/00 - C08F289/00
• CPC Class Codes: C08L 71/02 : Polyalkylene oxides
• CPC Class Codes: C09D 153/00 : Coating compositions based on block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Coating compositions based on derivatives of such polymers
• CPC Class Codes: C12N 11/04 : entrapped within the carrier, e.g. gel or hollow fibres
• CPC Class Codes: C12N 2533/30 : Synthetic polymers
• CPC Class Codes: C12N 2533/32 : Polylysine, polyornithine
• CPC Class Codes: C12N 2533/40 : Polyhydroxyacids, e.g. polymers of glycolic or lactic acid (PGA, PLA, PLGA); Bioresorbable polymers
• CPC Class Codes: C12N 2533/74 : Alginate
• CPC Class Codes: C12N 5/0012 : Cell encapsulation
• CPC Class Codes: C12N 5/0677 : Three-dimensional culture, tissue culture or organ culture; Encapsulated cells

Abstract

This invention provides novel methods for the formation of biocompatible membranes around biological materials using photopolymerization of water soluble molecules. The membranes can be used as a covering to encapsulate biological materials or biomedical devices, as a “glue” to cause more than one biological substance to adhere together, or as carriers for biologically active species. Several methods for forming these membranes are provided. Each of these methods utilizes a polymerization system containing water-soluble macromers, species, which are at once polymers and macromolecules capable of further polymerization. The macromers are polymerized using a photoinitiator (such as a dye), optionally a cocatalyst, optionally an accelerator, and radiation in the form of visible or long wavelength UV light. The reaction occurs either by suspension polymerization or by interfacial polymerization. The polymer membrane can be formed directly on the surface of the biological material, or it can be formed on material, which is already encapsulated.

Claims

1. A method of encapsulation comprising the steps of:

(a) creating a microcapsule within which is encapsulated at least one cell,

(b) coating the microcapsule with a photoinitiator,

(c) placing the microcapsule in an aqueous macromer solution comprised of macromer,

(d) exposing the aqueous macromer solution containing the microcapsule to light radiation,

(e) polymerizing the aqueous macromer solution, and

(f) forming a macrocapsule containing at least one microcapsule with at least one cell.

2. The method of claim 1, further comprising a step of coating the microcapsule with poly(L-lysine), between step (a) and step (b).

3. The method of claim 1, wherein the cell is an eukaryote cell.

4. The method of claim 3, wherein the eukaryote cell is a mammalian cell.

5. The method of claim 1, wherein the macrocapsule is a conformal coated microcapsule.

6. The method of claim 5, wherein the mammalian cell is a Human cell.

7. The method of claim 1, wherein the photoinitiator is any dye that absorbs light having a frequency between 320 nm and 900 nm, can form free radicals, is at least partially water soluble, and is non-toxic to the at least one cell at the concentration used for polymerization.

8. The method of claim 7, wherein the photoinitiator is selected from the group consisting of ethyl eosin, eosin Y, fluorescein, 2, 2-dimethoxy, 2-phenylacetophenone, 2-methyl, 2-phenylacetophenone, camphorquinone, rose bengal, methylene blue, erythrosin, phloxine, thionine, riboflavin, and methyl green.

9. The method of claim 1, wherein the macromer solution further comprises a primary, secondary, tertiary, or quaternary amine cocatalyst.

10. The method of claim 1, wherein the microcapsule is comprised of material selected from the group consisting of alginate, chitosan, agarose, gelatin, hyaluronic acid, chondroitin sulfate, dextran, dextran sulfate, heparin, heparin sulfate, heparan sulfate, gellan gum, xanthan gum, guar gum, water soluble cellulose derivatives and carrageenan.

11. The method of claim 1, wherein the macromer solution further comprises an accelerator to increase the rate of polymerization.

12. The method of claim 1, wherein the macromer is a water soluble, ethylenically unsaturated, polymer susceptible to polymerization into a water insoluble polymer through interaction of at least two carbon-carbon double bonds.

13. The method of claim 12, wherein the macromer is selected from the group consisting of ethylenically unsaturated derivatives of poly(ethylene oxide) (PEO), poly(ethylene glycol) (PEG), poly(vinyl alcohol) (PVA), poly(vinylpyrrolidone) (PVP), poly(ethyloxazoline) (PEOX), poly(amino acids), polysaccharides, and proteins.

14. The method of claim 13, wherein the macromer is PEG tetraacrylate.

15. The method of claim 13, wherein the polysaccharide is selected from the group consisting of alginate, hyaluronic acid, chondroitin sulfate, dextran, dextran sulfate, heparin, heparin sulfate, heparan sulfate, chitosan, gellan gum, xanthan gum, guar gum, water soluble cellulose derivatives and carrageenan.

16. The method of claim 13, wherein the protein is selected from the group consisting of gelatin, collagen, and albumin.

17. A method of encapsulation comprising the steps of:

(a) creating a microcapsule within which is encapsulated at least one aggregation of cells,

(b) coating the microcapsule with a photoinitiator,

(c) placing the microcapsule in an aqueous macromer solution comprised of macromer,

(d) exposing the aqueous macromer solution containing the microcapsule to light radiation,

(e) polymerizing the aqueous macromer solution, and

(f) forming a macrocapsule containing at least one microcapsule with at least one aggregation of cells.

18. The method of claim 17, further comprising a step of coating the microcapsule with poly(L-lysine), between step (a) and step (b).

19. The method of claim 17, wherein the macrocapsule is a conformal coated microcapsule.

20. The method of claim 17, wherein the cell is an eukaryote cell.

21. The method of claim 20, wherein the eukaryote cell is a mammalian cell.

22. The method of claim 21, wherein the mammalian cell is a Human cell.

23. The method of claim 17, wherein the photoinitiator is any dye that absorbs light having a frequency between 320 nm and 900 nm, can form free radicals, is at least partially water soluble, and is non-toxic to the at least one aggregation of cells at the concentration used for polymerization.

24. The method of claim 23, wherein the photoinitiator is selected from the group consisting of ethyl eosin, eosin Y, fluorescein, 2, 2-dimethoxy, 2-phenylacetophenone, 2-methyl, 2-phenylacetophenone, camphorquinone, rose bengal, methylene blue, erythrosin, phloxine, thionine, riboflavin, and methyl green.

25. The method of claim 17, wherein the macromer solution further comprises a primary, secondary, tertiary, or quaternary amine cocatalyst.

26. The method of claim 17, wherein the microcapsule is comprised of material selected from the group consisting of alginate, chitosan, agarose, gelatin, hyaluronic acid, chondroitin sulfate, dextran, dextran sulfate, heparin, heparin sulfate, heparan sulfate, gellan gum, xanthan gum, guar gum, water soluble cellulose derivatives and carrageenan.

27. The method of claim 17, wherein the macromer solution further comprises an accelerator to increase the rate of polymerization.

28. The method of claim 17, wherein the macromer is a water soluble, ethylenically unsaturated, polymer susceptible to polymerization into a water insoluble polymer through interaction of at least two carbon-carbon double bonds.

29. The method of claim 28, wherein the macromer is selected from the group consisting of ethylenically unsaturated derivatives of poly(ethylene oxide) (PEG), poly(ethylene glycol) (PEG), poly(vinyl alcohol) (PVA), poly(vinylpyrrolidone) (PVP), poly(ethyloxazoline) (PEOX), poly(amino acids), polysaccharides, and proteins.

30. The method of claim 29, wherein the macromer is PEG tetraacrylate.

31. The method of claim 29, wherein the polysaccharide is selected from the group consisting of alginate, hyaluronic acid, chondroitin sulfate, dextran, dextran sulfate, heparin, heparin sulfate, heparan sulfate, chitosan, gellan gum, xanthan gum, guar gum, water soluble cellulose derivatives and carrageenan.

32. The method of claim 29, wherein the protein is selected from the group consisting of gelatin, collagen, and albumin.

33. A method of encapsulation comprising the steps of:

(a) creating a microcapsule within which is encapsulated at least one islet,

(b) coating the microcapsule with a photoinitiator,

(c) placing the microcapsule in an aqueous macromer solution comprised of macromer,

(d) exposing the aqueous macromer solution containing the microcapsule to light radiation,

(e) polymerizing the aqueous macromer solution, and

(f) forming a macrocapsule containing at least one microcapsule with at least one islet.

34. The method of claim 33, further comprising a step of coating the microcapsule with poly(L-lysine), between step (a) and step (b).

35. The method of claim 33, wherein the macrocapsule is a conformal coated microcapsule.

36. The method of claim 33, wherein the cell is an eukaryote cell.

37. The method of claim 36, wherein the eukaryote cell is a mammalian cell.

38. The method of claim 37, wherein the mammalian cell is a Human cell.

39. The method of claim 33, wherein the photoinitiator is any dye that absorbs light having a frequency between 320 nm and 900 nm, can form free radicals, is at least partially water soluble, and is non-toxic to the at least one islet at the concentration used for polymerization.

40. The method of claim 39, wherein the photoinitiator is selected from the group consisting of ethyl eosin, eosin Y, fluorescein, 2, 2-dimethoxy, 2-phenylacetophenone, 2-methyl, 2-phenylacetophenone, camphorquinone, rose bengal, methylene blue, erythrosin, phloxine, thionine, riboflavin, and methyl green.

41. The method of claim 33, wherein the macromer solution further comprises a primary, secondary, tertiary, or quaternary amine cocatalyst.

42. The method of claim 33, wherein the microcapsule is comprised of material selected from the group consisting of alginate, chitosan, agarose, gelatin, hyaluronic acid, chondroitin sulfate, dextran, dextran sulfate, heparin, heparin sulfate, heparan sulfate, gellan gum, xanthan gum, guar gum, water soluble cellulose derivatives and carrageenan.

43. The method of claim 33, wherein the macromer solution further comprises an accelerator to increase the rate of polymerization.

44. The method of claim 33, wherein the macromer is a water soluble, ethylenically unsaturated, polymer susceptible to polymerization into a water insoluble polymer through interaction of at least two carbon-carbon double bonds.

45. The method of claim 44, wherein the macromer is selected from the group consisting of ethylenically unsaturated derivatives of poly(ethylene oxide) (PEG), poly(ethylene glycol) (PEG), poly(vinyl alcohol) (PVA), poly(vinylpyrrolidone) (PVP), poly(ethyloxazoline) (PEOX), poly(amino acids), polysaccharides, and proteins.

46. The method of claim 45, wherein the macromer is PEG tetraacrylate.

47. The method of claim 45, wherein the polysaccharide is selected from the group consisting of alginate, hyaluronic acid, chondroitin sulfate, dextran, dextran sulfate, heparin, heparin sulfate, heparan sulfate, chitosan, gellan gum, xanthan gum, guar gum, water soluble cellulose derivatives and carrageenan.

48. The method of claim 45, wherein the protein is selected from the group consisting of gelatin, collagen, and albumin.