Novel Composite Membrane Guides Cortical Bone Regeneration

Abstract

Current treatment options for restoring large bony defects due to trauma or tumor ablation are limited by the host bone tissue availability and donor site morbidity of bone implantation. Creation of implantable functional bone tissue that could restore bony defects may be a possible solution. Previously, many in vitro studies have indicated the potential of using electrospun nanofibrous scaffolds for tissue repair. However, few studies demonstrated their utility in tissue repair models. We hypothesized that the electrospun nanofibrous membrane improves the efficacy of currently-used collagenous guided bone regeneration (GBR) membrane in repairing large cortical bony defect. A practical biodegradable nanofibrous poly-L-lactic-acid (PLLA) membrane honeycombed with one layer of collagen matrix was developed. Bone defect with 10 x 15 mm2 area was covered by nanofiber-reinforced bi-layer membrane or collagenous membrane. 3 and 6 weeks after operation, bone defect healing was assessed radiologically and histologically. The radiolographic data showed that the group treated with nanofiber-reinforced bi-layer membrane had more bony tissue formation at 3 weeks. The histology results were consistent with that of radiographic findings at 3 weeks. Moreover, the defects treated with bi-layer membrane were repaired perfectly by dense cortical bone at 6 weeks, while whose treated with collagenous membrane were filled with spongy bone and fibrous tissues. The results demonstrated that electrospun nanofibrous membrane can be combined with collagenous GBR membrane to improve guided bone regeneration technology. And this type of membrane may provide implantable functional bone tissues for patients with large bone defects.