Preparation of Porous Poly (L-Lactic Acid) (PLLA) Scaffold by Porogen Leaching and Freeze Drying

The poly (L-lactic acid) (PLLA) porous scaffolds were prepared by porogen leaching combined freeze drying with the porogen particulates of ice in this paper. The ice particulates are made of distilled water sprayed into liquid nitrogen through a nozzle under a certain pressure. The pore morphology, porosity and residual porogen of the scaffolds was studied. There is no residual porogen when the ice particulate is used and the leaching mechanism of porogen is discussed. The scaffolds are composed of macro and micro pores and with a porosity of 80-90%. The macro pores are formed by ice particulate and the micro pores by thermal induced phase separation of solvent. The pore size can be changed easily by altering the size of ice particulate. The MTT assay was used to estimate cellular activity by L-929 cells culture in vitro. The results demonstrate that the scaffolds have no cytotoxicity. It could confidently be stated that the combined process seems to be a promising technique for the fabrication of porous polymer scaffold.