Dual Delivery of Growth Factors and or Antibiotics from Chitosan- Composites for Bone Regeneration

摘要

This one year project investigated (in vitro) the ability of microsphere-based chitosan-calcium sulfate composites to locally deliver growth factor and antibiotics to heal bone and prevent infection in traumatic musculoskeletal injuries. Antibiotic, vancomycin (vanc) was loaded into calcium sulfate (CaS) and microspheres loaded with either vanc or bone morphogenetic protein 2 (BMP-2). In vitro release was evaluated over 6 weeks and biological activity and interactions of released factors were evaluated in cultures. Composites released vanc at levels (>40microg/ml) that killed S. aureus for 18 days. BMP-2 release from microspheres was reduced to approximately 1ng/ml/day when combined with CaS as compared to plain microspheres (approximately 9ng/ml/day for days 6-10 elution). This may be due to high affinity of BMP for calcium and hence may serve to retain BMP in wound site. There was no overt toxicity with levels of vanc.