A porous silk fibroin membrane could be prepared through freeze-drying process with dense top surface porous bottom surface in low porosity and porous inner portion in high porosity .

采用冷冻干燥法可以制得下表面为致密结构， 上 表面为 孔隙率较小的多孔结构，而内部是孔隙率较大的多孔结构的丝素膜。