title: Characterization and performance of membranes designed for macroencapsulation/implantation of pancreatic islet cells.
abstract: Amphiphilic polymer membranes were synthesized for macroencapsulation of cells and characterized by select chemical and biological techniques. The membranes were prepared by crosslinking hydrophilic poly(N,N-dimethyl acrylamide) (PDMAAm) main chains with hydrophobic di-, tri-, and octa-methacrylate telechelic polyisobutylene (PIB) stars. The hydrophilic/hydrophobic composition and the molecular weights between crosslink sites (both M(c,hydrophilic) and M(c,hydrophobic)) were controlled by synthesis conditions. Small tubular membranes were made by in situ rotational copolymerization/crosslinking and filled with pancreatic rat islets. The water-swelling behavior, mechanical properties, and oxygen and insulin diffusion were studied. Macroencapsulatory performance of these membranes was investigated in vitro by macroencapsulation of pancreatic rat islets within tubular membranes for up to 1.5 months, and studying the insulin secreting ability of encapsulated islets in culture. The membranes are robust and maintain their integrity for the period of encapsulation. They allow oxygen and insulin diffusion. Macroencapsulated islets maintained their viability and insulin secretion over an extended period (i.e., 45 days).
authors.affiliation: Institute of Polymer Science, The University of Akron, Akron, OH 44325-3909, USA.
authors.forename: I S
authors.initials: IS
authors.lastname: Isayeva
authors.forename: B T
authors.initials: BT
authors.lastname: Kasibhatla
authors.forename: K S
authors.initials: KS
authors.lastname: Rosenthal
authors.forename: J P
authors.initials: JP
authors.lastname: Kennedy
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D002470:Cell Survival; D005947:Glucose / Q000378:metabolism; D066298:In Vitro Techniques; D007515:Islets of Langerhans / Q000166:cytology* / Q000378:metabolism*; D016381:Islets of Langerhans Transplantation / Q000379:methods; D008567:Membranes, Artificial; D010100:Oxygen / Q000378:metabolism; D019397:Pancreas, Artificial; D011108:Polymers / Q000378:metabolism*; D051381:Rats; D013718:Tensile Strength; D013997:Time Factors
chemical_list: D001672:Biocompatible Materials; D008567:Membranes, Artificial; D011108:Polymers; D005947:Glucose; D010100:Oxygen