Yulia Lumelsky

PolyHIPE are crosslinked highly porous polymers synthesized within high internal phase emulsions (HIPE). PolyHIPE have unusual fully­interconnected, open­pore structures, low bulk densities, high permeabilities, large surface areas, and the ability to rapidly absorb large quantities of liquid through capillary action. These unique qualities and the ability to tailor them through variations in the synthesis procedure seem especially suitable for the development of novel three dimensional scaffolds for such applications as tissue engineering and drug delivery. The main objectives of this research were: to synthesize and characterize novel polyHIPE that contain biodegradable polymers and to determine their suitability for tissue engineering by evaluating their interaction with cells, analyzing in vitro tissue growth and organization. Two different synthesis routes were used: (1) forming semi­interpenetrating polymer networks (s­IPN) containing biodegradable polymers within polyHIPE; (2) synthesizing polyHIPE copolymers with biodegradable macromonomers. Polycaprolactone (PCL) macromonomers were successfully incorporated into styrene- and acrylate-based polyHIPE using both the s­IPN and copolymer routes. The porous structures, densities, moduli, and water absorption of these novel polyHIPE were strongly dependent upon the composition. The acrylate­based polyHIPE copolymers containing 50% PCL were able to undergo complete hydrolytic degradation. Increasing the PCL content reduced HIPE stability, resulting in an increase in void size that, in turn, enhanced cell growth. Mouse skeletal cells were successfully attached to the polyHIPE surface and spontaneous differentiation was observed, suggesting that these polyHIPE may be good scaffolds for tissue growth.