Using biomimetically mineralized collagen membranes with different surface stiffness to guide regeneration of bone defects

Because guided bone regeneration (GBR) process is pronouncedly affected by the micro-environment in the defect, the surface stiffness of collagen membranes as a constituent part of the micro-environment was investigated in this study. The objective of this study was to manufacture biomimetically mineralized collagen membranes with controllable surface stiffness based on biomimetic strategy and to investigate the influences of surface stiffness on GBR process. The characterization and biocompatibility of membranes were examined in vitro. The mechanical properties of membranes were evaluated on macro and micro levels using tensile test and atomic force microscope, respectively. The critical-size cranial defect model and ectopic osteogenesis were chosen to employ their performances in vivo. The results indicated that the biomimetically mineralized collagen membranes with controllable surface stiffness were manufactured based on the biomimetic theory. The in vitro experiments showed that the mineralized collagen membrane with satisfactory surface stiffness can better promote the adhesion, proliferation, and osteogenic differentiation of mesenchymal stem cells. The membranes can perform excellently in both osteoinduction and osteoconduction, which results in effective manifestations in aspects of ectopic osteogenesis and GBR in vivo. Therefore, this biomimetically mineralized collagen membrane is a promising candidate for GBR treatment in future.