Structural alterations of adhesion mediating components in cells cultured on poly-beta-hydroxy butyric acid

Polymers may serve as a biodegradable material in tissue engineering. To as sess the biocompatibility of poly-p-hydroxy butyric acid (PHB), we studied the structural organization of cellular molecules involved in adhesion usin g osteoblastic and epithelial cell lines. On PHB, both cell lines revealed a rounded cell shape due to reduced spreading. The filamentous organization of the actin cytoskeleton was impaired. In double immunofluorescence analy ses we demonstrated that the colocalization of the fibronectin fibrils with the actin filaments was lost in cultures on PHB. Similarly, collagen II di stribution was altered, whereas the organization of collagen I was not obvi ously affected. Further evidence for impaired structural organization was o btained for the beta1-integrin receptor and vinculin which mediate the inte raction of the cytoskeleton with the extracellular matrix. In confluent epi thelial cells, the tight junction protein ZO-1 showed a larger lateral exte nsion in the cell-cell contacts when cells were grown on PHB. Because struc tural organization of components which mediate cell-matrix and cell-cell ad hesion controls cell physiology these parameters could be a sensitive indic ator for the biocompatibility of implant materials. (C) 2001 Elsevier Scien ce Ltd. All rights reserved.