The lack of autologous and allogeneic tissue suitable for transplantation has driven the development of the tissue engineering field, in which new tissues are created from cultured cells and biomaterials. This is advantageous because these cells can be expanded in vitro and cultured for use by multiple patients. The biomaterial serves as a vehicle to localize the cells of interest, a physical spacer to create potential space for tissue development, and as a template guiding tissue regeneration. Biodegradable homopolymers and copolymers of lactic and glycolic acid are attractive candidates for fabricating tissue engineering matrices due to their flexible and well defined physical properties and relative biocompatability. Additionally, the degradation product of these polymers are natural metabolites and are readily removed from the body.
The invention is directed to a process for preparing porous polymer materials by a combination of gas foaming and particulate leaching steps. The invention is also directed to porous polymer material prepared by the process, particularly having a characteristic interconnected pore structure, and to methods for using such porous polymer material, particularly for tissue engineering.