Biocompatibility and biodegradation of novel PHB porous substrates with controlled multi-pore size by emulsion templates method.

PHB porous substrates were prepared based on the mono-membrane fabricated by emulsion templates method. The key factors of the method affecting the pore size and porosity of the PHB porous substrates were studied. The surface of PHB porous substrates were investigated by scanning electron microscope (SEM), which showed the even pore size and regular arranged pore. The transect of the PHB porous substrates prepared using the templates method was good. Moreover, the effects of variation of surfactant content (P%) and water content (R) on the pore size and porosity of PHB films were discussed. Preliminary studies showed that when P% is less than 20%, the pore size made by emulsion templates ranged from 5 microm to 30 microm with the value of P increasing. As P% is up to 20%. It was interesting to see that the porous substrates had muti-pore size distribution, i.e., median pore sizes were about 5 microm and inside the wall of pore, there existed numerous micro-pores size can be controlled from 100 nm to 500 nm only by adjusting the parameter R of the microemulsion. The cell-compatibility was evaluated via Chinese Hamster Lung (CHL) fibroblast cultivation in vitro. The Cells were cultured on both the mono-pore size membrane prepared by emulsion templates and the multi-pore size membrane prepared by microemulsion templates. It can be seen that the cells cultured on multi-pore size membrane stretched their morphology and proliferated better than that of mono-pore size membrane. These results indicated that the multi-pore size membrane had better cell-compatibility and was more suitable for tissue engineering. The degradation experiment indicated that the degradation of PHB porous substrates were accelerated by enzyme in vitro and the porous configuration was favorable to its degradation.