Preparation and Properties of Sodium Alginate/Silk Fibroin Microcarriers

Injectable porous microcarriers, with excellent biocompatibility, biodegradability, high cell seeding density and simple implantable procedures in the body, have been widely used in bone tissue engineering. In this work sodium alginate/silk fibroin (SA/SF) porous microcarriers were prepared cross-linked by SrCl2 or CaCl2 using emulsion method combined with freeze-drying method. The morphology and structure of the microcarriers were characterized by scanning electron microscopy (SEM). The cell proliferation ability and osteogenic activity of the microcarriers were investigated by culturing rat bone marrow mesenchymal stem cells (rBMSCs). The SA/SF microcarriers showed an interconnective porous structure with an average particle size of 254.3 ± 50.0 μm and an average pore size of 42.0 ± 5.3 μm. The SA/SF microcarriers cross-linked with SrCl2 showed higher cell proliferation ability and osteoinductive ability than those cross-linked with CaCl2. These features indicated that the designed SA/SF microcarriers are ideal for tissue engineering.