Evaluation of the hydrophilized asymmetric pore sized polydioxanone membrane for guided bone regeneration

Bone defects occur in a variety of clinical situation, and their reconstruction to provide mechanical integrity to the skeleton is a necessary step in the patient rehabilitation. Bones can regenerate themselves to repair defects up to a certain size but sometimes the suitable implant materials have to be applied to facilitate the bone repair. As a part of the effort to improve the efficiency of bone repair, we evaluated the hydrophilized asymmetric pore sized polydioxanone membrane for guided bone regeneration. The polydioxanone membrane was fabricated to have different pore size at inner (around 50 nm in diameter) and outer surface (around 50 ?m in diameter) with an average 0.4 mm thickness. The cytotoxic effect of it was analyzed in vitro and the histocompatibility and guided bone regeneration effects were evaluated in vivo, respectively. The rat tibia bone defects measuring 7 mm×3 mm in size were treated with polydioxanone membrane with or without application of 10 mM LiCl or 100 ?g/ml T-CAM. The defects were evaluated at 3weeks after treatment by radiography and histology. The polydioxanone membrane was relatively resilient with some cushion. It was no cytotoxic and evoked neither an immune nor an inflammatory response. It was gradually absorbed by numerous multinucleated giant cells with time and completely disappeared within 8 weeks at rat subcutaneous pouches. The application of polydioxanone membrane at rat tibia bone defects induced more effective bone repair with matured cortical plate regeneration compared to none membrane applied group. In addition, the treatment of 10 mM LiCl and 100 ?g/ml T-CAM within polydioxanone membrane facilitated bony healing. These results suggest that the combined application of bioactive molecules such as 10 mM LiCl or 100 ?g/ml T-CAM with hydrophilized sized polydioxanone membrane can facilitate the guided bone regeneration.