Radiographic evaluation of healing of critical size calvarial defects treated with decellularised tissue engineered HAS i in rat models

Abstract

Extra cellular matrix (ECM) incorporated calcium hydroxyapatite bound with triphasic silica is a custom made bone graft with hybrid properties which is used for bone regeneration. A promising new technique for preparing natural matrices for bone regeneration now in trend is decellularisation. According to reports, the ECM activates mesenchymal stem cells, speeding up bone healing. Although research employing hard tissues like bone are scarce, successful decellularisation has been done using a variety of tissues including skin, cartilage and tendon. The study was carried out in rat calvaria; critical size defects were created and later grafted with decellularised tissue engineered HASi bioceramic (test) and plain HASi bioceramic (control) on left and right side respectively. Radiography was used to assess changes in the graft, the rate of its degradation and the degree of bone repair. Postoperative dorsoventral view of the skull was taken immediately after surgery and thereafter on 2nd, 4th, 8th and 12th week post-surgery. The grafts were found to remain stable throughout the healing period. By 4th week onwards signs of gradual degradation of material with regeneration of bone could be noticed especially on test side compared to control. Test material was found to be completely integrated with host bone by eight weeks whereas control graft took 12 weeks. At twelve weeks, both the test and control grafts showed complete integration with host bone. It was concluded that the test graft material successfully hastened bone regeneration, making it a promising alternative to conventional bone grafts.