Characterization of cortical astrocytes on materials of differing surface chemistry

The behavior of cortical astrocytes was evaluated on a number of medically relevant materials of differing physicochemical properties. This study desc ribes cell attachment, DNA synthesis, production of extracellular matrix (E CM) proteins, and neuronal interactions of perinatal rat astrocytes in vitr o. The number of attached astrocytes initially differed among the materials , decreasing with increasing material hydrophobicity. In contrast, the rate of DNA synthesis increased with increasing material hydrophobicity. With t he exception of only one material, astrocytes reached confluence by 12 days in culture on all the materials tested. Furthermore, the expression of cha racteristic ECM proteins and the fundamental ability of astrocytes to suppo rt neuronal attachment and growth was qualitatively identical between popul ations of astrocytes on different materials. The ability of astrocytes to c olonize different surfaces initially was mediated via adsorbed serum protei ns, as reducing the capacity of a model surface to adsorb proteins inhibite d astrocyte colonization for up to 2 weeks in culture. We propose that astr ocytes are relatively insensitive to differences in surface chemistries so long as the proteins necessary for cellular attachment are capable of adsor bing to the material to some extent. It seems likely that the ability of as trocytes to produce and remodel a matrix creates a surface environment that eventually becomes similar regardless of the surface chemistry of the unde rlying material. (C) 1999 John Wiley & Sons, Inc.