Poly(ethylene glycol)

  • Amarpreet S. Sawhney


The demands placed on a material to be used for microencapsulation are stringent. The material should (1) be stable in the physiological environment over several years, (2) not engender any cytotoxicity, (3) be permselective so as to be immunoprotective and yet allow nutrient and metabolite access, and (4) be biocompatible so as not to elicit an inflammatory or fibrotic response from the host. Of the wide range of materials used, ionically coacervated microcapsules of alginate and poly(1-lysine) (PLL) have shown promise. O’Shea and Sun (1986) demonstrated rat islet survival times of 2 to 3 months, and occasionally of 1 year, in mice, using alginate/PLL/alginate trilayered microcapsules. The xenografts apparently failed as a result of over-growth with fibroblast-like and macrophage-like cells upon the microcapsules. This cellular overg-rowth is due to a nonspecific foreign body reaction elicited by the microcapsules and is by no means restricted to alginate/PLL/alginate microcapsules. Roberts et al, using HEMA-MMA copolymers for microencapsulation, also reported seeing up to a 10 μJim thick layer of cellular overgrowth after 4 weeks in vivo (Roberts et al 1991).


Graft Copolymer Acryloyl Chloride Free Radical Propa Encapsulate Islet Reduce Protein Adsorption 
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  1. Andrade JD, Hlady V. 1986. Protein adsorption and materials biocompatibility: a tutorial review and suggested hypotheses. Adv Polym Sci 79:1–63.CrossRefGoogle Scholar
  2. Andrade JD, Nagoaka S, Cooper S, Okano T, Kim SW. 1987. Surfaces and blood biocompatibility. Current hypothesis. ASAIO Trans 10:75–76.CrossRefGoogle Scholar
  3. Buck CA, Horwitz AF. 1987. Cell surface receptors for extracellular matrix molecules. Ann Rev Cell Biol 3:179–205.PubMedCrossRefGoogle Scholar
  4. Dawson RM, Broughton RL, Stevenson WTK, Sefton MV. 1987. Microencapsulation of CHO cells in a hydroxyethyl methacrylate-methyl methacrylate copolymer. Biomaterials 8:360–366.PubMedCrossRefGoogle Scholar
  5. Dupuy B, Gin H, Baquey C, Ducassou D. 1988. In vitro polymerization of a microencapsulating medium around living cells. J Biomed Mater Res 22:1061–1070.PubMedCrossRefGoogle Scholar
  6. Fan M-Y, Lum Z-P, Fu X-W, Levesque L, Tai IT, Sun AM. 1990. Reversal of diabetes in BB rats by transplantation of encapsulated pancreatic islets. Diabetes 39:519–522.PubMedCrossRefGoogle Scholar
  7. Ishihara K, Nakabayashi N. 1990. Adhesive bone cement both to bone and metals: 4-META in MM A initiated with tri-n-butyl borane. J Biomed Mater Res 23:1475–1482.CrossRefGoogle Scholar
  8. Kam TI. 1990. Effects of visible radiation on cultured cells. Photochem and Photobiology 53(6): 1089.Google Scholar
  9. Kobayashi H, Hyon S-H, Ikada Y. 1991. Water-curable and biodegradable prepolymers. J Biomed Mater Res 25:1481–1494.PubMedCrossRefGoogle Scholar
  10. Koehnlein HE, Lemperle G. 1969. Experimental studies with a new gelatin-resorcin-formaldehyde glue. Surgery 66:377–382.PubMedGoogle Scholar
  11. Lacy PE, Hegre OD, Gerasimidi-Vazeou A. 1991. Maintenance of normoglycemia in diabetic mice by subcutaneous xenografts of encapsulated islets. Science 254:1782–1784.PubMedCrossRefGoogle Scholar
  12. Lim F, Sun AM. 1980. Microencapsulated islets as a bioartificial pancreas. Science 210:908–910.PubMedCrossRefGoogle Scholar
  13. Luckham P, Klein J. 1985. Interactions between smooth solid surfaces in solutions of adsorbing and nonadsorbing polymers in good solvent conditions. Macromolecules 18:721.CrossRefGoogle Scholar
  14. Lyman MD, Melanson, D, Sawhney, AS. 1996. Characterization of the formation of interfacially photopolymerized thin hydrogels in contact with arterial tissue. Biomaterials 17:359–364.PubMedCrossRefGoogle Scholar
  15. McMahon J, Schmid S, Weislow O, Stinson S, Camalier R, Gulakowski R, Shoemaker R, Kiser R, Dykes D, Harrison S, Mayo J, Boyd MJ. 1990. Feasibility of cellular microencapsulation technology for evaluation of anti-human immunodeficiency virus drugs in vivo. J Natl Cancer Inst 82:1761.PubMedCrossRefGoogle Scholar
  16. O’Shea GM, Goosen MFA, Sun AM. 1984. Prolonged survival of transplanted islets of Langerhans encapsulated in a biocompatible membrane. Biochim Biophys Acta 804:133–136.PubMedCrossRefGoogle Scholar
  17. O’Shea GM, Sun AM. 1986. Encapsulation of rat islets of Langerhans prolongs xenograft survival in diabetic mice. Diabetes 35:943–946.PubMedCrossRefGoogle Scholar
  18. Pathak CP, Sawhney AS, Hubbell JA. 1992. Rapid photopolymerization of immunoprotective gels in contact with cells and tissue. J Am Chem Soc 114:8311–8312.CrossRefGoogle Scholar
  19. Potts TV, Petrou A. 1991. Argon laser initiated resin photopolymerization for the filling of root canals in human teeth. Lasers Surg Med 11:257–262.PubMedCrossRefGoogle Scholar
  20. Roberts T, deBoni T, Sefton MV. 1991. Microencapsulation of dopamine secreting cells (PC 12) in a HEMAMMA copolymer. Trans Soc Biomater 14:157.Google Scholar
  21. Ronis ML, Harvick JD, Fung R, Dellavecchia M. 1984. Review of cyanoacrylate tissue glues with emphasis on their otorhinolaryngological applications. Laryngoscope 94:210–213.PubMedCrossRefGoogle Scholar
  22. Sawhney AS. 1992. Biocompatible microspheres and microcapsules for animal tissue encapsulation and transplantation. Dissertation. University of Texas at Austin, Austin, Texas.Google Scholar
  23. Sawhney AS, Hubbell JA. 1992. Polyethylene oxide)graft-poly(l-lysine) copolymers to enhance the biocompatibility of poly(l-lysine)-alginate microcapsule membranes. Biomaterials 13:863–870.PubMedCrossRefGoogle Scholar
  24. Sawhney AS, Pathak CP, Hubbell JA. 1994. Modification of Langerhans surfaces with immunoprotective poly(ethylene glycol) coatings. Biotech Bioeng 44:383–386.CrossRefGoogle Scholar
  25. Tanaka A, Yasuhara S, Osumi M, Fukui S. 1977. Immobilization of yeast microbodies by inclusion with photocrosslinkable resins. Eur J Biochem 80:193–197.PubMedCrossRefGoogle Scholar
  26. Yashon D, Jane JA, Gordon MC. 1966. Effects of methyl-2-cyanoacrylate adhesives on the somatic vessels and the central nervous system of animals. J Neurosurg 25:883–888.Google Scholar

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© Springer Science+Business Media New York 1999

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  • Amarpreet S. Sawhney

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