A comparative study on the bone repair effects of two kinds of tissue regeneration membranes / 中国组织工程研究

ABSTRACT

BACKGROUND: Our previous study confirmed that BTO/P(VDF-TrFE) piezoelectric nanocomposite membrane containing 5%BTO (BaTO3, BTO) nanoparticles could significantly promote bone marrow mesenchymal stem cells (BMSCs) adhesion, growth, osteogenic differentiation and repair of bone defects due to its bionic potential. However, for clinical applications, it is not clear whether there is any difference between the bone repair effect of this material as a guide for tissue regeneration and that of the existing clinically non-degradable membrane products. OBJECTIVE: To compare the effects of BTO/P(VDF-TrFE) piezoelectric nano-composite membrane materials with commercial PTFE membrane in repairing critical-sized defects of SD rat skull. METHODS: BTO/P(VDF-TrFE) piezoelectric nanocomposite membrane containing 5% BTO nanoparticles was prepared by solution casting method. Scanning electron microscope, atomic force microscope and water contact angle measuring instrument were used to observe the surface morphology, measure the surface roughness and surface hydrophilicity and hydrophobicity of the material. In SD rats (purchased from the Laboratory Animal Center, Beijing University Hospital of Stomatology, China), a 5-mm sized full-thick bone defect was made on both sides of the sagittal suture of the skull. The left bone defect was covered with PTFE membrane (control group). The right bone defect was covered with BTO/P(VDF-TrFE) piezoelectric nano-composite membrane (experimental group). At postoperative 4 and 12 weeks, micro-CT and histological methods were used to evaluate the repair of the skull defect in rats. This study was approved by Animal Ethics Committee, Beijing University Hospital of Stomatology. RESULTS AND CONCLUSION: The piezoelectric nanocomposite membrane had smooth and dense surface and BTO nanoparticles were evenly distributed. PTFE membrane was composed of loose coarse fibers. The piezoelectric nanocomposite membrane had lower surface roughness (P<0.001) and higher hydrophilicity (P<0.001) than PTFE membrane. Micro-CT and histological results showed that at 4 weeks after surgery, new bone formation was found in both groups, but new bone formation was more obvious in the center of the defect in the experimental group than in the control group. At 12 weeks after surgery, bone defects healed in both groups, but the maturity of newly formed bone in the experimental group was greater than that in the control group. These results suggest that BTO/P(VDF-TrFE) piezoelectric nanocomposite membrane containing 5%BTO (BaTO3, BTO) nanoparticles can be used as a membrane guiding tissue regeneration.