Preparation of porous materials by selective enzymatic degradation: effect of in vitro degradation and in vivo compatibility.

Poly(butylene succinate) (PBS) and poly(lactic acid) (PLA) were melt-blended and formed into a film by hot press forming. The film was selectively degraded by cutinase and proteinase K to form a porous material. The porous materials were characterized with respect to their pore morphology, pore size, porosity and hydrophilicity. The porous materials were investigated in vitro degradation and in vivo compatibility. The results show that the pore size of the prepared porous materials could be controlled by the proportion of PBS and the degradation time. When the PBS composition of PBS/PLA blends was changed from 40 wt% to 50 wt%, the mean pore diameter of the porous materials significantly increased from 6.91 µm to 120 µm, the porosity improved from 81.52% to 96.90%, and the contact angle decreased from 81.08° to 46.56°. In vitro degradation suggests that the PBS-based porous materials have a good corrosion resistance but the PLA-based porous materials have degradability in simulated body fluid. Subcutaneous implantation of the porous materials did not cause intense inflammatory response, which revealed good compatibility. The results of hematoxylin and eosin and Masson's trichrome staining assays demonstrated that the porous materials promote chondrocyte production. Porous materials have great potential in preparing implants for tissue engineering applications.