Gels for encapsulation of biological materials

• US 5,801,033 A
• Filed: 06/07/1995
• Issued: 09/01/1998
• Est. Priority Date: 02/28/1992
• Status: Expired due to Term

• 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: Pathak, Chandrashekhar P., Sawhney, Amarpreet S., Desai, Neil P., Hossainy, Syed F. A., Hubbell, Jeffrey A.
• Primary Examiner(s): Lilling, Herbert J.
• Application Number:
  US08/480,678
• Time in Patent Office: 1,182 Days
• Field of Search: 435/177, 435/178, 435/182, 522/87, 522/88, 522/89, 522/121, 522/149, 522/151, 522/154, 522/158, 522/181, 522/186, 525/54.1, 525/54.2, 525/54.26, 525/54.22, 527/201, 424/93.1, 424/487, 424/489, 424/493, 427/494
• US Class Current: 435/182
• CPC Class Codes: A61K 2035/128 capsules, e.g. microcapsules
• 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 27/36 containing ingredients of undetermined constitution or reaction products thereof , e.g. transplant tissue, natural bone, extracellular matrix isolated natural compounds, e.g. collagen A61L27/24
• CPC Class Codes: A61L 27/3683 subjected to a specific treatment prior to implantation, e.g. decellularising, demineralising, grinding, cellular disruption/non-collagenous protein removal, anti-calcification, crosslinking, supercritical fluid extraction, enzyme treatment
• CPC Class Codes: A61L 27/38 containing added animal cells organs or tissue containing native cells A61L27/36
• CPC Class Codes: A61L 27/3804 characterised by specific cells or progenitors thereof, e.g. fibroblasts, connective tissue cells, kidney cells
• 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 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. An encapsulated biological material comprising a biological material enclosed within an encapsulating membrane, said encapsulated biological material produced by a process comprising the steps of:

providing the biological material, wherein the biological material is selected from the group consisting of tissue, cells, subcellular organelles, and subcellular non-organelle components;

mixing the biological material in an aqueous macromer solution comprising macromer and photoinitiator to form a mixture, said macromer comprising a water-soluble polymer having at least two sites of unsaturation;

forming geometric shapes from said mixture; and

polymerizing the macromer by exposing the geometric shapes to light radiation to form the encapsulating membrane surrounding the biological material.

2. The encapsulated material of claim 1, further comprising a microcapsule layer interposed between the biological material and the encapsulating membrane.

3. The encapsulated material of claim 1, 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.

4. The encapsulated material of claim 1, wherein the PEG is PEG tetraacrylate which has a molecular weight around 18,500 D.

5. The encapsulated material of claim 1, wherein the polysaccharides are 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.

6. The encapsulated material of claim 1, wherein the proteins are selected from the group consisting of gelatin, collagen and albumin.

7. The encapsulated material of claim 1, wherein the macromer is of the formula ##STR4## where F₁ =CONH, COO or NHCOO

X=H, CH₃, C₂ H₅, C₆ H₅, Cl, Br, OH or CH₂ COOH

F₂ =COO, CONH, O or C₆ H₄,

R=CH₂ or -alkyl-,

n≧

5, and

m≧

2.

8. The encapsulated material of claim 1, wherein the macromer solution further comprises a cocatalyst and the photoinitiator is selected from the group consisting of ethyl eosin, eosin Y, fluorescein, 2,2-dimethoxy-2-phenylacetophenone, 2-methoxy-2-phenylacetophenone, camphorquinone, rose bengal, methylene blue, erythrosin, phloxime, thionine, riboflavin and methylene green.

9. The encapsulated material of claim 1, wherein the radiation has a wavelength between 350 nm and 700 nm.

10. The encapsulated material of claim 1, wherein the biological material is selected from pancreatic islet cells, human foreskin fibroblasts, Chinese hamster ovary cells, beta cell insulomas, lymphoblastic leukemia cells, mouse 3T3 fibroblasts, dopamine secreting ventral mesencephalon cells, neuroblastoid cells, adrenal medulla cells, and T-cells.

11. An encapsulated biological material comprising a biological material enclosed within an encapsulating membrane, said encapsulated biological material produced by a process comprising the steps of:

providing the biological material, wherein the biological material is selected from the group consisting of tissue, cells, subcellular organelles, and subcellular non-organelle components;

coating the biological material with photoinitiator;

suspending the coated biological material in an aqueous macromer solution, said macromer comprising a water-soluble polymer having at least two sites of unsaturation; and

irradiating the suspension with light radiation to form the encapsulating membrane surrounding the biological material.

12. The encapsulated material of claim 11, further comprising a microcapsule layer interposed between the biological material and the encapsulating membrane.

13. The encapsulated material of claim 11, 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 encapsulated material of claim 11, where in the PEG is PEG tetraacrylate which has a molecular weight around 18,500 D.

15. The encapsulated material of claim 11, wherein the polysaccharides are 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 encapsulated material of claim 11, wherein the proteins are selected from the group consisting of gelatin, collagen and albumin.

17. The encapsulated material of claim 11, wherein the macromer is of the formula ##STR5## where F₁ =CONH, COO or NHCOO

X=H, CH₃, C₂ H₅, C₆ H₅, Cl, Br, OH or CH₂ COOH

F₂ =COO, CONH, O or C₆ H₄,

R=CH₂ or -alkyl-,

n≧

5, and

m≧

2.

18. The encapsulated material of claim 11, wherein the macromer solution further comprises a cocatalyst and the photoinitiator is selected from the group consisting of ethyl eosin, eosin Y, fluorescein, 2,2-dimethoxy-2-phenylacetophenone, 2-methoxy-2-phenylacetophenone, camphorquinone, rose bengal, methylene blue, erythrosin, phloxime, thionine, riboflavin and methylene green.

19. The encapsulated material of claim 11, wherein the radiation has a wavelength between 350 nm and 700 nm.

20. The encapsulated material of claim 11, wherein the biological material is selected from pancreatic islet cells, human foreskin fibroblasts, Chinese hamster ovary cells, beta cell insulomas, lymphoblastic leukemia cells, mouse 3T3 fibroblasts, dopamine secreting ventral mesencephalon cells, neuroblastoid cells, adrenal medulla cells, and T-cells.

21. An encapsulated biological material comprising:

a biological material selected from the group consisting of viable pancreatic islet cells, human foreskin fibroblasts, Chinese hamster ovary cells, beta cell insulomas, lymphoblastic leukemia cells, mouse 3T3 fibroblasts, dopamine secreting ventral mesencephalon cells, neuroblastoid cells, adrenal medulla cells, and T-cells; and

an encapsulating membrane surrounding the biological material, wherein the membrane comprises a macromer selected from the group consisting of 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, and wherein the macromer has been polymerized or crosslinked by exposing the macromer to light radiation in order to form a continuous membrane surrounding the biological material.