Osteoblast responses to collagen-PVA bioartificial polymers in vitro: the effects of cross-linking method and collagen content.

A range of 'bioartificial' collagen/poly(vinyl alcohol) blends have been produced, cast as films and cross-linked using either glutaraldehyde or a dehydrothermal treatment (DHT). Films were used as substrates for the culture of osteoblast-like cells. The attachment, adhesion and proliferative responses of these cells to the range of films were examined using proliferation assays, light, electron and confocal microscopy. There was an inverse relationship between collagen content of gluataraldehyde cross-linked films and the extent of cell proliferation on them. A cytotoxicity assay demonstrated no toxic effect related to increasing collagen content. The greatest differences in cell responses observed were associated with the choice of cross-linking method. Films cross-linked with glutaraldehyde showed variation related to collagen content in cell adhesion, proliferation and morphology. Such differences were not apparent with the DHT cross-linked films. Collagen/PVA 'bioartificial' films can be dehydrothermally cross-linked to increase biological stability and reduce water solubility. The method of cross-linking employed is the greater influence in determining osteoblast compatibility with these materials. The DHT cross-linking method is a preferable alternative to the use of glutaraldehyde. Collagen/PVA bioartificial films cross-linked by the DHT method have shown potential for biocompatibility with osteoblasts.