Biodegradable Porous Polymers through Emulsion Templating

Highly porous, emulsion-templated polymers, polyHIPE, that are synthesized within high internal phase emulsions (HIPE) combine a fully interconnected open-pore structure with mechanical integrity and the ability to absorb relatively large amounts of liquid through capillary action. Biodegradable polyHIPE would be of interest for tissue engineering scaffold applications. This paper describes the synthesis of both styrene-based and acrylate-based polyHIPE containing as much as 50 wt % of a biodegradable polycaprolactone (PCL) oligomer. The addition of PCL destabilizes the HIPE, yielding a partial collapse of the porous structure. This collapse yields a decrease in the relative mass of water absorbed, although the volumetric ratio of water absorbed to pore volume increases. The relatively low modulus, acrylate-based polyHIPE with 50% PCL underwent swelling, absorbing more than twice its pore volume. This polyHIPE also underwent extensive degradation, indicating that the PCL degradation promotes the disintegration of the macromolecular structure.