Injectable vancomycin‐loaded silk fibroin/methylcellulose containing calcium phosphate‐based in situ thermosensitive hydrogel for local treatment of osteomyelitis: Fabrication, characterization, and in vitro performance evaluation

Abstract

AbstractThe conventional treatment of osteomyelitis with antibiotic‐loaded nondegradable polymethylmethacrylate (ATB‐PMMA) beads has certain limitations, including impeded bone reconstruction and the need for secondary surgery. To overcome this challenge, this study aimed to develop and characterize an injectable vancomycin‐loaded silk fibroin/methylcellulose containing calcium phosphate‐based in situ thermosensitive hydrogel (VC‐SF/MC‐CAPs). The VC‐SF/MC‐CAPs solution can be easily administered at room temperature with a low injectability force of ≤30 N and a high vancomycin (VC) content of ~96%. Additionally, at physiological temperature (37 °C), the solution could transform into a rigid hydrogel within 7 minutes. In vitro drug release performed under both physiological (pH 7.4) and infection conditions (pH 4.5) revealed a prolonged release pattern of VC‐SF/MC‐CAPs following the Peppas–Sahlin kinetic model. In addition, the released VC from VC‐SF/MC‐CAPs hydrogels exhibited antibacterial activity against Staphylococcus aureus for a period exceeding 35 days, as characterized by the disk diffusion assay. Furthermore, at pH 7.4, the VC‐SF/MC‐CAPs demonstrated >60% degradation within 35 days. Importantly, when exposed to physiological pH conditions, CAPs are transformed into bioactive hydroxyapatite, which benefits bone formation. Therefore, VC‐SF/MC‐CAPs showed significant potential as a local drug delivery system for treating osteomyelitis.