CELLULAR-RESPONSES TO CHEMICAL AND MORPHOLOGIC ASPECTS OF BIOMATERIALSURFACES .1. A NOVEL IN-VITRO MODEL SYSTEM

The clinical success of any implant is directly dependent upon the cel lular behavior in the immediate vicinity of the interface established between the host tissue and the biomaterial(s) used to fabricate the d evice, All biomaterials have morphologic, chemical, and electrical sur face characteristics that influence the cellular response to the impla nt. Quantitative measurement of specific aspects of this local host re sponse to different but well-characterized biomaterial surfaces provid es a crucial link in the understanding of the overall phenomenon of im plant biocompatibility. A system has been devised for in vitro examina tion of responses of cells to controlled but independent changes in bo th the chemistry and morphology of polystyrene (PS) tissue culture sur faces. Micromachined silicon wafers wore used as templates to solvent- cast PS replicas [using 0, 1, or 2 wt % styrene (S) monomer additions] with either none, 0.5- or 5.0-mu m-deep surface grooves arranged in a radial array. When all possible morphologies were combined with all p ossible polymers, nine model biomaterial surfaces (MBSs) were produced . The chemical characteristics of the MBSs were determined using elect ron spectroscopy for chemical analysis, secondary ion mas's spectrosco py, and contact angle techniques and were found to be distinct. The ty pes and amount of proteins that adsorb onto these surfaces from serum containing media were examined and found to consist of multiple molecu lar layers of relatively uniform composition. Self-contained tissue cu lture vessels formed from the MBSs were capable of supporting the grow th of confluent cultures of rat calvarial cells. The model biomaterial system described here can be used to examine how simultaneous stimuli resulting from the chemical and morphological characteristics of a te st material may influence biologic responses. Such multifactorial bioc ompatibility research is needed to properly document material-host int eractions. (C) 1995 John Wiley and Sons, Inc.