Improvement of osteogenesis and antibacterial properties of a bioactive glass/gelatin-based scaffold using zoledronic acid and CM11 peptide

This study aimed to investigate the effects of zoledronic acid (ZA) and antibacterial CM11 peptide on the osteoinduction and antibacterial properties of bioactive glass (BG). The bioactive glass/gelatin (BG/Gel) composite was synthesized using the sol-gel method. The 2-x minimum inhibitory concentration of the peptide and 4.00 mg mL-1 of ZA were added to the BG/Gel during fabrication. The BG/Gel composite morphological and structural characteristics and anti-bacterial activities were analyzed using Fourier transform infra-red spectroscopy, scanning electron microscopy and disk diffusion test, respectively. The release of the peptide and ZA from BG/Gel was measured using ultra-violet spectroscopy. After 14 days, the effects of the peptide/ ZA-containing BG/Gel (PZ-BG/Gel) on the growth and differentiation of mesenchymal stem cells were evaluated using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide, calcium and alkaline phosphatase assays, immunocytochemical staining for osteocalcin (OCN) and real-time polymerase chain reaction for OCN, type I collagen, bone morphogenetic protein 2 and Runt-related transcription factor-2 genes. The disk diffusion test showed the anti-microbial activity of the scaffold against multi-drug-resistant isolates of Pseudomonas aeruginosa and Staphylococcus aureus. Analyses showed a significantly higher level of stem cells differentiation into the osteo-genic cells in PZ-BG/Gel scaffold compared to BG/Gel scaffold alone. Accordingly, osteoblast markers were significantly increased in comparison with the control. In conclusion, the osteo-induction and antibacterial properties of BG-based scaffold can be improved using ZA and CM11.