A Study Of Bone Regeneration Of The Antibacterial Nanocomposite Membrane In Vivo

An excellent inresorbable guided bone regeneration (GBR) membrane should meet the following requirements: good biocompatibility and safety, the ability of being lightly bioresorbed after functional action, adequate mechanical strength to maintain a secluded space for newly formed bone, easiness of being operated. The Ag-nHA-nTiO₂/PA66 is composed of polyamide fibers and silver-hydroxyapatite-titania nanoparticles which are similar to the microstructure of the bone in micro-composition and characteristics. It has satisfactory biocompatibility as well. And addition of silver ion and titanium dioxide endues the composite material with wonderful antibacterial efficiency. The objective of our study is to observe the effect of Ag-nHA-nTiO₂/PA66 as guided bone regeneration (GBR) in the skull defects of rats so as to make preparation for its clinical application.Four kinds of biomaterials were implanted into muscles of rats. After 1, 4, 8 weeks , the retrieved samples from the animals were examined through histopathology and scanning electron microscopy to evaluate the biocompatibility of the biomaterials above.Then two 5mm trephined defects were produced in skull of each rat. The defects were treated and covered by Ag-nHA-nTiO₂/PA66, by nHA/PA66, PA66 and ePTFE membranes. And a group filled with autogenous blood only as empty control. The regeneration of bone in the defects was examined by radiography, histology, biochemistry, scanning electronic microscopy and mufti-media computer estimation at 1,4 and 8 weeks after the operations respectively.The results indicated that the Ag-nHA-nTiO₂/PA66 material had excellent biocompatibility and biodegraded very slowly in 8 weeks in vivo. It guided the bone regeneration at the defect region well 8 weeks after the operations. The defects in the rats covered by Ag-nHA-nTiO₂/PA66 membrane were almost filled by bone. A quantitative radiographic analysis showed that Ag-nHA-nTiO₂/PA66 membrane had equivalent effect to ePTFE and nHA/PA66 membrane in quantity of the newly formed bone (P>0.05). And that there was significantly more bone bridged in the Ag-nHA-nTiO₂/PA66 group than that in PA66 defects and in empty control groups (P<0.05). The newly developed Ag-nHA-nTiO₂/PA66 membrane can be an ideal GBR material as compared with some other materials based on the results of this animal study.