DESCRIPTION: Many new polymer systems are being developed to accommodate biomaterial needs bone reconstruction. However, despite significant advances in the development of newer tissue engineering technologies to better approximate the complex three-dimensional nature of complex tissue equivalents, it has remained a challenge to develop clinically applicable bone replacement materials at least in part due to the difficulty to seed relatively thick scaffolds with cells (>1 mm) and to maintain cell viability for prolonged periods of time in vitro as well as in vivo. It is the purpose of this grant application to develop strong, bioactive biopolymeric bone graft materials using nanoparticulate hydroxyapatite ("nano-HA"). The overall objective is to employ nanoparticle technology to biopolymeric scaffolds to improve their ability to support cell penetration and maintain mechanical stability at bony repair sites. This Phase I project will investigate the feasibility of enhancing tissue responses in, as well as the mechanical integrity of, bony defects subject to repair or void filling using scaffold fashioned from a biopolymeric foam made via the crosslinking of poly(propylene glycol-co-fumaric) acid (PPF) in the presence of effervescent filters. PROPOSED COMMERCIAL APPLICATION: Bone is the second most implanted material in the body after blood. There are over 450,000 bone graft procedures annually in the U.S. (2.2 million worldwide) with a market potential of $400 to $600 million. New tissue engineered bone replacement materials would find a niche in this ever growing market.