In vitro and in vivo evaluation of protamine-heparin membrane for microencapsulation of rat Langerhans islets.
Rat pancreatic islets were microencapsulated with multilayer protamine-heparin (PH) membrane. Basal and stimulatory insulin secretion of microencapsulated islets was similar to the controlled free islets in vitro. During the long-term culture (up to 2 weeks) mean insulin release of encapsulated islets did not significantly differ from the mean of free ones (the ratio of mentioned means was 54-167%). Empty PH microcapsules transplanted into Wistar rats intraperitoneally and under the kidney capsule were generally harmless up to 4 months. In only a few cases traces of fibrotic tissue around capsules entrapped in the omentum were found. No damage of microcapsules structure was observed. The worst results were obtained in the instance of retroperitoneal transplantation. We conclude, therefore, that PH membrane was proved to be highly biocompatible, nontoxic for islets, and did not impair viability and glucose-dependent insulin secretion of Langerhans islets in in vitro culture.
Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw.
K
K
Tatarkiewicz
E
E
Sitarek
P
P
Fiedor
M
M
Sabat
T
T
Orłowski
D000818:Animals; D001672:Biocompatible Materials; D002478:Cells, Cultured; D006493:Heparin; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000166:cytology / Q000378:metabolism; D016381:Islets of Langerhans Transplantation; D008297:Male; D008567:Membranes, Artificial; D011479:Protamines; D051381:Rats; D017208:Rats, Wistar
D001672:Biocompatible Materials; D007328:Insulin; D008567:Membranes, Artificial; D011479:Protamines; D006493:Heparin