Silk fibroin regulates osteoconduction of hydroxyapatite in rat spine fusion model

Abstract

The purpose of this study was to use a rat spinal fusion model to determine whether osteoconduction of HA is improved by the addition of SF. The SF/HA composite was derived by mixing HA sols with SF sols. In an in vitro study, water absorption testing, cell compatibility and compression test were done. In an in vivo study, 30 S-D male rats had surgery for posterolateral lumbar fusion. Group I rats were implanted with SF/HA composites; Group II rats were implanted with HA; Group III rats were implanted with an autograft. Fusion was evaluated by water absorption test, manual palpation, radiology and histology. The results showed that water absorption was significantly higher with the SF/HA composite compared with HA. Manual palpation and radiology showed a higher rate of fusion in the SF/HA group. Histology also showed better results for the SF/HA group. In, conclusion, SF can modify the osteoconduction of HA. SF/HA composites make good bone graft alternatives in spinal fusion, although additional research needs to be done.