Biological component comprising artificial membrane

• US 20040063200A1
• Filed: 07/22/2003
• Published: 04/01/2004
• Est. Priority Date: 07/28/2000
• Status: Active Grant

• Current Assignee: Emory University
• Original Assignee: Emory University
• Inventors: Orban, Janine M., Chaikof, Elliot, Faucher, Keith M., Liu, Hongbo, Sun, Xue Long, Feng, June
• Granted Patent: US 7,713,544 B2
• Time in Patent Office: Days
• US Class Current: 435/317.1
• CPC Class Codes: A61K 9/1273 Polymersomes; Liposomes with polymerisable or polymerised bilayer-forming substances polymers grafted or coated on phosphatidyl liposomes A61K9/1271, on non-phosphatidyl liposomes A61K9/1272
• 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 15/32 Proteins, polypeptides; Degradation products or derivatives thereof, e.g. albumin, collagen, fibrin, gelatin A61L15/225 takes precedence
• CPC Class Codes: A61L 27/222 Gelatin
• CPC Class Codes: A61L 27/227 Other specific proteins or polypeptides not covered by A61L27/222, A61L27/225 or A61L27/24
• CPC Class Codes: A61L 27/24 Collagen
• CPC Class Codes: A61L 27/507 for artificial blood vessels apparatus for applying cells on a blood vessel prosthesis A61F2/062
• CPC Class Codes: A61L 33/0082 by reacting with an organic compound other than heparin
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: B82Y 5/00 Nanobiotechnology or nanomedicine, e.g. protein engineering or drug delivery
• CPC Class Codes: C07F 9/6552 the oxygen atom being part of a six-membered ring
• CPC Class Codes: C08F 220/281 and containing only one oxygen, e.g. furfuryl (meth)acrylate or 2-methoxyethyl (meth)acrylate
• CPC Class Codes: C12N 1/00 Microorganisms, e.g. protozoa; Compositions thereof medicinal preparations containing material from protozoa, bacteria or viruses A61K35/66, from algae A61K36/02, from fungi A61K36/06; preparing medicinal bacterial antigen or antibody compositions, e.g. bacterial vaccines, A61K39/00; Processes of propagating, maintaining or preserving microorganisms or compositions thereof; Processes of preparing or isolating a composition containing a microorganism; Culture media therefor

Abstract

A biocompatible biological component is provided comprising a membrane-mimetic surface film covering a substrate. Suitable substrates include hydrated substrates, e.g. hydrogels which may contain drugs for delivery to a patient through the membrane-mimetic film, or may be made up of cells, such as islet cells, for transplantation. The surface may present exposed bioactive molecules or moieties for binding to target molecules in vivo, for modulating host response when implanted into a patient (e.g. the surface may be antithrombogenic or antiinflammatory) and the surface may have pores of selected sizes to facilitate transport of substances therethrough. An optional hydrophilic cushion or spacer between the substrate and the membrane-mimetic surface allows transmembrane proteins to extend from the surface through the hydrophilic cushion, mimicking the structure of naturally-occurring cells. An alkylated layer directly beneath the membrane-mimetic surface facilates bonding of the surface to the remainder of the biological component. Alkyl chains may extend entirely through the hydrophilic cushion when present. To facilitate binding, the substrate may optionally be treated with a polyelectrolyte or alternating layers of oppositely-charged polyelectrolytes to facilitate charged binding of the membrane-mimetic film or alkylated layer beneath the membrane-mimetic film to the substrate. The membrane-mimetic film is preferably made by in situ polymerization of phospholipid vesicles.

Claims

1. A biological component comprising an artificial membrane and a substrate.

2. The biological component of claim 1 wherein the artificial membrane comprising a phospholipid membrane-mimetic surface.

3. The biological component of claim 2 wherein said phospholipid is selected from the group consisting of phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, ether-based phospholipids, lipopeptide conjugates, and glycolipid conjugates.

4. The biological component of claim 1 wherein said substrate is selected from the group consisting of implantable prostheses, artificial organs, cells, drug delivery device, or therapeutic devices.

5. The biological component of claim 1 wherein said substrate is a hydrogel.

6. The biological component of claim 1 wherein said substrate is selected from the group consisting of gelatin, collagen, alginate, and chitosan and comprises a bioactive substance.

7. The biological component of claim 6 wherein said substrate is an alginate comprising a bioactive substance.

8. The biological component of claim 1 wherein said substrate is a cell selected from the group consisting of islet cells, hepatocytes, parathyroid cells, thyroid cells neurons, sertoli cells, and genetically engineered cells designed to secrete bioactive compounds.

9. The biological component of claim 1 wherein said membrane-mimetic surface comprises pores of a selected size.

10. The biological component of claim 1 wherein said membrane-mimetic surface has been functionalized to modulate interactions between a cell, tissue, blood, organ or other living material and said membrane surface, or the substrate on which said membrane or surface has been placed.

11. The biological component of claim 9 where such modulated interactions are selected from the group consisting of reduction of thrombogenicity, reduction of inflammatory response, selective transport of molecules through said membrane, and sequestering of particles from the host into which the biological component has been placed.

12. The biological component of claim 1 wherein a polyelectrolyte is completed onto said substrate, and said membrane-mimetic surface is attached thereto.

13. The biological component of claim 1 comprising a hydrophilic polymer cushion between said substrate and said membrane-mimetic surface.

14. The biological component of claim 13 also comprising a polyelectrolyte complexed onto said substrate.

47. The biological component of claim 2 wherein said membrane-mimetic surface comprises a polymerized phosphatidylcholine phospholipid.

77. A method for delivering a drug comprising incorporating said drug into a biological component of claim 1.

78. The method of claim 77 wherein said drug is incorporated into said substrate.

79. A method of minimizing or abrogating a host inflammatory response to an implanted substrate of claim 1 comprising:

incorporating into the artificial membrane of claim 1 a moiety having anti-inflammatory effect.

80. The method of claim 77 wherein said moiety is that of a molecule selected from the group consisting of thrombomodulin, endothelial cell protein C receptor, vascular ATP diphosphohydrolase, hirudin, annexin, HLA-G, IL-10, hyaluronan, heparan sulfate, heparin, chondroitin sulfate, keratan sulfate, dermatan sulfate and anti-inflammatory analogs of the foregoing.

81. The method of claim 77 wherein said anti-inflammatory moiety is incorporated into said membrane-mimetic surface.

82. The method of claim 77 wherein said substrate is selected from the group consisting of islet cells, hepatocytes, parathyroid cells, thyroid cells, neurons, sertoli cells and genetically engineered cells designed to secrete bioactive compounds.

15. A biological component comprising a hydrated substrate coated with a stable, alkylated surface by the steps of:

complexing a polyelectrolyte onto the hydrated substrate, and

coating the surface of the polyelectrolyte with an oppositely charged amphiphilic polymer containing long-chain alkanes.

16. The biological component of claim 15 wherein a membrane-mimetic surface is formed on the alkylated surface.

17. The biological component of claim 15 wherein said substrate comprises one or more materials selected from the group consisting of cells, and natural or synthetic polysaccharides and proteins which complex with a polyelectrolyte.

18. The biological component of claim 17 wherein said material comprises a natural or synthetic collagen, gelatin, alginate, recombinant collagen protein or protein-mimetic polypeptide polymer.

19. The biological component of claim 15 wherein said hydrated substrate comprises a bioactive molecule.

20. The biological component of claim 19 wherein said bioactive molecule enhances cell viability or function, or minimizes local host inflammatory responses.

21. The biological component of claim 15 wherein said hydrated substrate is comprised within openings in a device for implantation into a patient.

22. The biological component of claim 15 wherein said hydrated substrate is coated onto a surface of a device for implantation into a patient.

23. The biological component of claim 22 wherein said device is selected from the group consisting of dialysis tubing, dialysis membranes, hollow fibers, membrane oxygenators, artificial blood vessels, artificial heart valves, left ventricular assist devices, artificial hearts, artificial lungs, artificial kidneys, artificial livers, vascular grafts, artificial heart valves, artificial joints, catheters, synthetic and intraocular lenses, electrodes, artificial cartilage, ligaments, tendons, bones and bone grafts, tissue reinforcements, tissue scaffolds including tissue scaffolds comprising cells and/or tissues, cell-containing capsules, intraluminal stents for use within blood vessels, biliary system or hollow organs.

24. The biological component of claim 15 wherein said hydrated substance is coated onto the lumenal surface of a porous or nonporous conduit.

25. The biological component of claim 15 wherein said polyelectrolyte is alginate or poly-L-lysine.

26. The biological component of claim 15 wherein alternating layers of oppositely-charged polyelectrolytes are complexed onto said hydrated substrate.

27. The biological component of claim 16 wherein said membrane-mimetic surface comprises a phospholipid.

28. The biological component of claim 16 wherein said phospholipid is selected from the group consisting of phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, ether-based phospholipids, lipopeptide conjugates, and glycolipid conjugates.

29. The biological component of claim 28 wherein said ether-based phospholipids are selected from the group consisting of dialkyl (C10-C20) ether-linked phospholipid, mono and dialkenyl (C10-C20) ether-linked phospholipid.

30. The biological component of claim 28 wherein said lipopeptide conjugates are selected from the group consisting of biologically active synthetic, recombinant, or native peptides conjugated to a lipid group.

31. The biological component of claim 28 wherein said glycolipid conjugates are selected from the group consisting of synthetic or native oligosaccharides, polysaccharides, glycosaminoglycans, including derivatives of heparan sulfate, chondroitin sulfate, dermatan sulfate, keratan sulfate, and hyaluronan conjugated to a lipid group.

32. The biological component of claim 27 wherein said phospholipid is selected from the group consisting of acryloyloxy, methacryloyl, dienoyl sorbyl, acrylide, acrylonitrile, N-vinyl pyrrolidone, mono-acrylates, bis-acrylates, mono-dienes, bis-dienes, mono-diacetylene, bis-acetylene, mono-styryl groups, bis-styryl groups, mono-thiols, bis-thiols, mono-disulfides, and bis-disulfides.

33. The biological component of claim 27 wherein said phospholipid contains at least one polymerizable group.

34. The biological component of claim 27 wherein said phospholipid contains only one polymerizable group.

35. The biological component of claim 27 wherein said phospholipid comprises a mixture of polymerizable and non-polymerizable phospholipids whereby non-polymerized domains comprise membrane bound receptors.

36. The biological component of claim 16 wherein said membrane-mimetic surface comprises a polymerized phosphatidylcholine phospholipid.

37. The biological component of claim 16 wherein said membrane-mimetic surface is formed by in situ polymerization of a phospholipid on said alkylated surface.

38. The biological component of claim 37 wherein said polymerization is performed by fusion of said phospholipid followed by photopolymerization.

39. The biological component of claim 16 wherein said membrane-mimetic surface is formed by photocrosslinking of lipid molecules to functionalities on said alkylated surface.

40. The biological component of claim 16 comprising between said membrane-mimetic surface and said substrate a synthetic self-assembling amphiphile selected from the group consisting of polymers comprising an anchoring component and a hydrophilic spacer component.

41. The biological component of claim 40 wherein said self-assembling amphiphile also comprises a self-assembling hydrophobic component.

42. The biological component of claim 41 wherein said self-assembling amphiphile comprises a terpolymer comprised of:

a) an anchoring group which is a saturated or unsaturated single long chain alkane with optional terminal functionalities to facilitate crosslinking reactions with the supported lipid assembly;

b) a hydrophilic spacer which is a saturated or unsaturated group with two or more long chain alkane units with optional terminal functionalities to facilitate crosslinking reactions with the supported lipid assembly; and

c) a self-assembling hydrophobic component which is a saturated or unsaturated, symmetric or asymmetric boloamphiphile with one or more long chain alkane with optional terminal Tonalities to facilitate functionalization of the membrane-mimetic surface with bioactive molecules.

43. The biological component of claim 41 wherein said self-assembling amphiphile comprises a terpolymer comprising 2-hydroxymethyl acrylate (HEA), 3-acryloyl-3-oxapropyl-3-(N,N-dioctadecylcarbamoyl)-propionate (AOD), and styrene sulfonate in a molar ratio of 6:

3;

1.

44. The biological component of claim 43 wherein said substrate is alginate coated with poly-L-lysine.

45. The biological component of claim 41 wherein said amphiphile comprises a copolymer comprising of 2-hydroxymethyl acrylate (HEA) and 3-acryloyl-3-oxapropyl-3-(N,N-dioctadecylcarbamoyl)-propionate (AOD) in a 1:

1 molar ratio.

46. The biological component of claim 45 wherein said copolymer is applied directly to an alginate substrate.

48. The biological component of claim 16 wherein said membrane-mimetic surface comprises pores of a selected size.

49. The biological component of claim 34 wherein said pores are of a size selected from the group consisting of about 20 to 50 Å

, 50 to 100 Å

, 20 to 50 Å and

100 to 250 Å

, plus or minus about ten percent.

50. The biological component of claim 16 wherein an antithrombogenic membrane-mimetic surface is formed by incorporating an antithrombogenic moiety into said surface in an amount sufficient to minimize thrombogenesis.

51. The biological component of claim 16 wherein said antithrombogenic moiety is a moiety of an antithrombotic, antiplatelet, or profibrinolytic agent.

52. The biological component of claim 51 wherein said antithrombogenic moiety is comprised in a molecule selected from the group consisting of thrombomodulin, endothelial cell protein C receptor, vascular ATP diphosphohydrolase, hirudin, and lysine.

53. The biological component of claim 51 wherein said antithrombogenic moiety is added to a phospholipid prior to polymerization in situ.

54. The biological component of claim 51 wherein a lipid-modified thrombomodulin mutant is added to said phospholipid.

55. The biological component of claim 54 wherein said antithrombogenic moiety comprises extracytoplasmic domains of thrombomodulin.

56. The biological component of claim 54 wherein said lipid-modified thrombomodulin mutant is selected from the group consisting of a thrombomodulin fragment generated enzymatically, synthetically, or by recombinant methods, containing any or all of the extracellular domain which includes EGF repeats 4-6.

57. A biological component comprising a membrane-mimetic surface of claim 16 designed to minimize a host inflammatory response comprising a neoglycocalyx formed on said membrane-mimetic surface using a synthetic or natural glycosaminoglycan.

58. The biological component of claim 57 wherein said synthetic or natural glycosaminoglycan is selected from the group consisting of heparin, heparan sulfate, chondroitin sulfate, dermatan sulfate, keratan sulfate, and hyaluronan and anti inflammatory analogs thereof linked to said membrane-mimetic surface in an amount effective to minimize a host inflammatory response.

59. The biological component of claim 58 wherein said amount of surface area coverage of between about 10 and about 100%.

60. The biological component comprising a membrane-mimetic surface of claim 16 designed to minimize a host inflammatory response comprising a synthetic hydrophilic polymer selected from the group consisting of polyethylene oxide, polyacrylamide, poly(hydroxymethyl acrylate) (poly(HEA)), poly(hydroxymethyl methacrylate) (poly(HEMA)), and poly(vinylpyrollidone) linked to said membrane-mimetic surface in an amount effective to minimize a host inflammatory response.

61. The biological component of claim 16 wherein said membrane-mimetic surface comprises a targeting moiety linked thereto.

62. The biological component of claim 61 wherein said targeting moiety is selected from the group consisting of Avidin, Streptavidin, thiol-containing proteins, polypeptides, peptides, polysaccharides, lectin, enzymes and antibodies.

63. A method of forming an alkylated surface on a hydrated substrate comprising:

complexing polyelectrolyte onto the hydrated substrate, and

coating the surface of the polyelectrolyte with an oppositely charged amphiphilic polymer containing long-chain alkanes.

64. A method of forming biological component comprising polymerizing a membrane-mimetic lipid onto the amphiphilic polymer of claim 63.

65. The method of claim 65 comprising forming pores in said membrane-mimetic surface.

66. The method of claim 65 comprising incorporating particles selected from the group consisting of albumin, nanospheres and dendrimers, of a selected size and shape, into said membrane-mimetic surface.

67. The method of claim 66 wherein each arm of said dendrimers is terminated with a moiety that can be linked to said biological component.

68. The method of claim 67 wherein said moiety is covalently linked to said biological component.

69. The method of claim 67 wherein said moiety is non-covalently linked to said biological component.

70. The method of claim 67 wherein said moiety is linked to said membrane-mimetic surface.

71. The method of claim 67 wherein said moiety is linked to said biological component beneath said membrane-mimetic surface.

72. The method of claim 66 wherein said particles are dendrimers selected from the group consisting of polyethylene oxide, polyacrylamide, poly(hydroxymethyl acrylate) (poly(HEA)), poly(hydroxymethyl methacrylate) (poly(HEMA)), poly(vinylpyrollidone), polyacrylic acid, polystyrene and block copolymers thereof.

73. The method of claim 66 wherein pores are formed in said membrane-mimetic surface by insertion of natural or artificial pores.

74. The method of claim 65 wherein pores are formed in said membrane-mimetic surface by insertion of artificial or natural transporter molecules.

75. A biological component comprising a hydrated substrate with a membrane-mimetic surface, said surface being formed by the steps of:

complexing a polyelectrolyte onto the hydrated substrate, and then

coating the surface of the polyelectrolyte with an oppositely charged amphiphilic polymer derivatized with a compound selected from the group consisting of phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, and lipid-like boloamphiphiles.

76. The biological component of claim 75 wherein said polyelectrolyte is selected from the group consisting of alginate and poly-L-lysine.