Development of biodegradable polyesterurethane membranes with different surface morphologies for the culture of osteoblasts

To evaluate the biocompatibility of biodegradable polyesterurethane membran es with different surface morphologies for their possible use as orthopedic biomaterials, rat osteoblasts were cultured on smooth, sunken, and particu late polyesterurethane membranes. A close interaction between cells and exp osed particles on the particulate membranes was found. Cells on the particu late surfaces were well spread and flattened and had the greatest adhesion while cells on the smooth surfaces were more rounded, less spread, and less adhered. In addition, in order to investigate their in vivo degradation ra tes, the morphologic changes in retrieved membranes from 2, 4, and 8 weeks after subcutaneous implantation were observed by scanning electron microsco py and their average molecular weight changes were determined by gel permea tion chromatography. These analyses showed that smooth membranes, compared with the two other surface membrane types, had the greatest rate and degree of molecular weight change. In contrast, the molecular weight of particula te membranes, which favor the osteoblast culture, had not changed significa ntly at 8 weeks postimplantation. Thus particulate polyesterurethane membra ne surfaces may be of use as an orthopedic biomaterial, and polyesteruretha ne membranes certainly provide an ideal system for further study of the rel ative contributions to biocompatibility and degradation derived from surfac e morphology. (C) 2000 John Wiley & Sons, Inc.