THE DIFFERENTIAL-EFFECTS OF POLY(2-HYDROXYETHYL METHACRYLATE) AND POLY(2-HYDROXYETHYL METHACRYLATE) POLY(CAPROLACTONE) POLYMERS ON CELL-PROLIFERATION AND COLLAGEN-SYNTHESIS BY HUMAN LUNG FIBROBLASTS/

Because of its chemical versatility and demonstrated biocompatibility, poly(2-hydroxyethyl methacrylate) (pHEMA) has been widely used as a p olymer for biomedical applications. Since this hydrophilic material sh ows a poor interface with cells, blendings with other polymers were do ne to improve cytocompatibility. In our polymer, the presence of hydro phobic dominions on the material surface, due to the interpenetrating polymerization of pHEMA with poly(caprolactone) (PCL), seems to amelio rate the cytocompatibility in terms of cell adhesion and metabolism. F or our experiments, we used IMR-90 human fibroblasts, as these cells s trongly regulate DNA, RNA, and protein synthesis as anchorage-dependen t variables. Cell attachment on a pHEMA/PCL interpenetrating polymer n etwork was optimal, suggesting a strong adhesion between the cells and the polymer surface. Cell adhesion was weaker on pHEMA, as a signific ant fraction of the fibroblasts revealed a lack of spreading, with mos t cells remaining spherical. Moreover, only fibroblasts seeded on pHEM A significantly decreased mRNA synthesis; collagen production and cell shapes ranged from fully flat and proliferating, to minimally spread and nonproliferating. Finally, DNA synthesis, as a measure of cell pro liferation, was markedly inhibited in cells cultured on pHEMA but not on pHEMA/PCL. Ln conclusion, our results suggest that control of cell growth and metabolism by biomedical polymers is based on physicochemic al mechanism(s) in which the hydrophilicity/hydrophobicity ratio of th e material surfaces may play an important role. (C) 1997 John Wiley & Sons, Inc.