(745e) Injectable PolyHIPEs as High Porosity Bone Grafts

Tissue engineered bone grafts have the potential to repair critical size defects when traditional transplants are unavailable or fail. Scaffold architecture is a key determinant in the clinical success of bone grafts. Specifically, modulation of pore size and interconnectivity is necessary to promote osteoblast proliferation and nutrient/waste transport. Current fabrication techniques focus on generating biodegradable and injectable scaffolds that have suitable mechanical properties. The process of emulsion templating allows for creation of high internal phase emulsions (HIPEs), that upon polymerization form highly porous scaffolds (polyHIPEs). The scaffold architecture (interconnectivity, pore size, porosity) can be readily tuned by varying the processing parameters. We propose to create a series of polyHIPE scaffolds that are both biodegradable and injectable by utilizing polyester-based macromers. Our previous work with poly(ester urethane urea) polyHIPEs resulted in elastomeric foams that cure at body temperature with pore sizes ranging from 5-100 µm and compressive moduli ranging from 0.1-1.5 MPa. The addition of a more rigid polymer network, such as an acrylated ester, was investigated to generate an interpenetrating network with improved mechanical properties. The interaction between the two networks and their effects on the scaffold architecture, pore size, and mechanical properties will be presented.