A 3D porous microsphere with multistage structure and component based on bacterial cellulose and collagen for bone tissue engineering

•A 3D porous microsphere based on COL and BC was prepared by the template method combined with reverse-phase suspension regeneration.•The microspheres effectively promoted the adhesion, proliferation, and osteogenic differentiation of mice MC3T3-E1 cells.•The study can provide a theoretical basis for the application of COL/BC porous microspheres in the field of bone tissue engineering. Collagen (COL) and bacterial cellulose (BC) were chemically recombined by Malaprade and Schiff-base reactions. A three-dimensional (3D) porous microsphere of COL/BC/Bone morphogenetic protein 2 (BMP-2) with multistage structure and components were prepared by the template method combined with reverse-phase suspension regeneration. The microspheres were full of pores and had a rough surface. The particle size ranged from 8 to 12 microns, the specific surface area (SBET) was 123.4 m2/g, the pore volume (VPore) was 0.59 cm3/g, and the average pore diameter (DBJH) was 198.5 nm. The adsorption isotherm of the microspheres on the N2 molecule belongs to that of mesoporous materials. The microspheres showed good biocompatibility, and the 3D porous microspheres with multiple structures and components effectively promoted the adhesion, proliferation, and osteogenic differentiation of mice MC3T3-E1 cells. The study can provide a theoretical basis for the application of COL/BC porous microspheres in the field of bone tissue engineering.