Biological properties of an anti-bacterial membrane for guided bone regeneration: an experimental study in rats

The biosafety and efficacy of silver-hydroxyapatite-titania/polyamide nanocomposite (nAg-HA-TiO(2)/PA) membrane as a guided bone regeneration (GBR) barrier were investigated based on a rat subcutaneous and critical-size calvarial defect model.

Thirty-six Sprague-Dawley albino rats were divided into nAg-HA-TiO(2)/PA membrane test, expanded polytetrafluoroethylene (e-PTFE) membrane control and blank control. Inflammatory response and bone regeneration in each group were evaluated using morphological, serological, radiographic and histological techniques at 1, 4 and 8 weeks, respectively, after implantation.

For subcutaneous implantation, slight degradation of nAg-HA-TiO(2)/PA membranes was observed by scanning electron microscope at 4 and 8 weeks. Histopathologic examination demonstrated a thinner layer of granulation tissue in the vicinity of nAg-HA-TiO(2)/PA membranes than that of e-PTFE membranes. For cranial defect implantation, the serum alkaline phosphatase level was remarkably higher in nAg-HA-TiO(2)/PA group than that in e-PTFE group. Radiographic and histomorphometric analysis showed a fully closed cranial defect for both nAg-HA-TiO(2)/PA and e-PTFE groups at 8 weeks. No remarkable difference was found between the two groups regarding the integral optical density of neo-bone at each time interval.

nAg-HA-TiO(2)/PA membranes demonstrated better biocompatibility and similar osteoinductive activity compared with e-PTFE membranes. nAg-HA-TiO(2)/PA composite membranes provided a good prospect for further research and development in anti-bacterial GBR membrane.