The studies presented in this paper evaluate the modulatory role of protein pre-adsorbed polydimethylsiloxane (PDMS) and Biomer on the secretion of fibroblast stimulating growth factors from human monocytes/macrophages. The results of these studies show that Biomer and PDMS selectively activate human monocytes to produce fibroblast "progression-like" and to a lesser extent "competence-like" stimulating growth factors. Polydimethylsiloxane stimulated the monocytes/macrophages to produce more "progression-like" fibro-blast stimulating growth factors than Biomer. The induction of "competence-like" fibroblast stimulating activity from the monocytes was enhanced by preadsorption of PDMS with human derived fibrinogen, fibronectin, IgG, hemoglobin, or albumin. This phenomenon was not observed with protein pre-adsorbed Biomer. These studies support the hypothesis that protein pre-adsorbed polymers will selectively modulate monocyte/macrophage activation and induction of growth factors which have the potential to participate in tissue-implant interactions in vivo.