Improved Orthopedic Implant Surface Coatings

Endosseous metallic implants are common alloplastic devices used in medicine and dentistry. The orthopedic and dental marketplace continues to grow and indications for implants are expanding. There is a perceived need to improve both the successful healing (osseointegration) and the long term outcome of implants by control of interfacial reactivity during healing and remodeling. The growth of knowledge of bone biology and the expansion of biotechnology permits the present consideration of specifying one or more interfacial biologic activities to an endosseous metallic implant by use of a natural or synthetic bioactive agent (growth factor, extracellular matrix protein, small molecule). Potential examples of relevant interfacial actions include osteoinduction specified by BMPs, inhibition of resorption specified by OPG, inhibition of inflammation TNFR antagonists, or prevention of infection by anti-microbial or anti-fouling molecules. Each interfacial action is of related significance to one or more endosseous metallic implant application used today. The main obstacle facing the direct specification of a biological activity or activities to an endosseous metallic implant surface is the attachment of the specifying agent to the metallic surface without compromising the underlying mechanical properties of the implant or the function of the specifying bioactive agent. In this proposal we present a novel approach for specifying the biologic activity of titanium implant surfaces. Affinergy has developed a generalized approach to creating target surface-specific biopolymers that irreversibly bind specifying bioactive agents to the endosseous implant surface. These specifying and grafting biopolymers are termed a "interfacial biomaterials" (IFBM). The bi-functional IFBM has the unique advantages of a) providing requisite surface binding specificity, b) comprising robust chemistry for broad-based applications and c) offering capacity to specify a wide range of associated or independent biological activities onto a single metallic surface. The goal of this phase I SBIR proposal is to validate the IFBM approach to specifying a biological activity to titanium endosseous implants. The results of this research will establish the foundation for direct translation of IFBM-modified endosseous implants to clinical applications.