Reinforced chitosan membranes by microspheres for guided bone regeneration

In order to improve the osteogenic activity and mechanical strength of the guided bone regeneration (GBR) membrane for repairing bone defect, nano-hydroxyapatite/chitosan (nHA/CS) composite microspheres were prepared through in situ biomimetic method, then composite microspheres were incorporated into CS membrane. The morphologies and mechanical properties of the composite membranes were investigated through scanning electronic microscopy (SEM) and universal mechanical testing machine. The results show that the in situ biomimetic nHA/CS microspheres were embedded in CS membrane and were integrated tightly with CS matrix. The mechanical properties of GBR membranes containing in situ nHA/CS microspheres is significantly higher than that of membranes containing pure CS microspheres and blending nHA/CS microspheres. Its elongation rate at break reaches 5.61 +/- 0.95%. The elastic modulus and strength of the GBR membranes can reach 766.27 +/- 20.68 and 43.32 +/- 0.95 MPa, respectively. Further, The work-of-fracture of the membranes with in situ microspheres approaches 2.71 +/- 0.25 J/m(2), which is about 3 times of the pure CS membrane. The cell culture results display that the GBR membranes containing in situ biomimetic nHA/CS microspheres exhibit good cytocompatibility.