PREPARATION OF INSULIN-IMMOBILIZED POLYURETHANES AND THEIR INTERACTION WITH HUMAN FIBROBLASTS

Insulin-immobilized polyurethanes (PU) were prepared by the graft poly merization of acrylic acid on oxygen plasma-treated PU, followed by a coupling reaction with polyethylene oxide (PEO) and subsequently with insulin. Modified PUs were characterized by measuring the water contac t angle, the electron spectroscopy for chemical analysis and the atten uated total reflection Fourier-transform infrared spectroscopy. The we ttabilities of the PU surfaces were increased by the introduction of a crylic acid, PEO and insulin. The amount of insulin immobilized was co ntrolled by changing the concentrations of grafted acrylic acid and PE G. The interactions of human fibroblasts with surface-modified PUs wer e investigated using [H-3]-thymidine incorporation and optical microsc opy. Compared to the PU control, the proliferation of cells on the ins ulin-immobilized PUs was accelerated irrespective of the presence of s erum while it was not influenced by PEO grafting. It seemed to be cert ain, from the experiments with high performance liquid chromatography, that A chain of insulin mainly reacted with the amine-end group of PE O grafted during the immobilization reaction. (C) 1998 Published by El sevier Science Ltd. All rights reserved.