可降解新型聚乳酸膜在引导骨组织再生中的应用OA

Objective This work aimed to explore the application effect of a new biodegradable polylactic acid mem-brane(PDLLA/PLLA)in guiding bone tissue regeneration.Methods A total of 24 New Zealand white rabbits,weighing 2.5～3.0 kg,were prepared at the lower edge of the mandible near the body of the mandible on one side of the animal.The dimensions of the bone defect were 5 mm×3 mm.The animals were randomly divided into the experimental group,con-trol group,and blank group,with eight animals in each group.The experimental group animals were filled with Bio-oss bone powder,and PDLLA/PLLA was covered on the defect surface.The control group animals were filled with Bio-oss bone powder,and a Guidor polylactic acid membrane was covered on the defect surface.The blank group animals were not treated.At 8 and 12 weeks after the operation,specimens of the defect were collected for gross observation,micro-CT examination,and histopathological observation.Re-sults During the experiment,no inflammation and re-jection reaction occurred in the experimental animals in each group,and the wounds in each group healed well and osteogenesis was active.The gross observation showed that the animals in the experimental group had more bone for-mation and less material degradation at 8 weeks after the operation,whereas the animals in the control group had less bone formation and complete material degradation compared with the experimental group.At 12 weeks after the opera-tion,the amount of bone formation of animals in the experimental group and the control group was the same,but the mate-rials in the experimental group were further degraded.The amount of bone formation of animals in the blank group was less than that in the experimental group and the control group.At 8 and 12 weeks after the operation,micro-CT revealed that the new bone in the defect area of the experimental group and the control group was significantly more than that of the blank group.At 8 and 12 weeks after the operation,the bone volume/tissue volume(BV/TV),bone mineral density(BMD)and trabecular number(Tb.N)of the new bone in the experimental group and the control group were significantly higher than those in the blank group.Histological analysis demonstrated that the cells surrounding the new bone trabecu-lae in the experimental group grew actively at 8 weeks after the operation,and a small amount of osteoblasts and osteo-clasts were visible.At 12 weeks after the operation,a large number of osteoblasts and osteoclasts were found around the bone trabeculae of the experimental group animals,and the bone tissue density at the bone defect site was close to the sur-rounding normal bone tissue.Conclusion Thus,the new polylactic acid membrane(PDLLA/PLLA)has good biocom-patibility and bone conductivity,and it can significantly promote the healing of defects.