Anti-inflammatory properties of triblock siloxane copolymer-blended materials

Implantable biomaterials often trigger a variety of adverse responses. Beca use polydimethyl siloxane surfaces have good hemo- and bio-compatibility, i t is generally believed that surface biocompatibility may be improved by mo difying biomaterial surfaces with silicone-like properties. For this, we de veloped a series of polycaprolactone-polydimethylsiloxane-polycaprolactone (PDMS-PCL) copolymers. By mixing the substrate material-polyvinyl chloride- with law concentrations (1.2 and 2.4%) of the PDMS-PCL copolymer, we genera ted materials with silicone-like surface properties as reflected by increas ed surface silicon content and surface contact angles. We assessed the bioc ompatibility of these surfaces in vitro and found that the addition of PDMS -PCL significantly reduced the percentages of surface-'denatured' fibrinoge n, a critical element of genesis of many adverse responses to implanted bio materials. Indeed, using an animal implantation model, we find that PDMS-PC L-blended materials triggered significantly weaker inflammatory responses t han did polyvinyl chloride, the substrate control. The results from these e xperiments suggest that the use of PDMS-PCL additives (2.4%) in polymer ble nds is a useful means of camouflaging the substrate surface properties and improving the biocompatibility of biomaterials. (C) 1999 Elsevier Science L td. All rights reserved.