Bioactive Porous Hydrogel Based on Dicalcium silicate/chitosan/polyvinylpyrrolidone Loaded with Gentamicin for Bone Regeneration and Osteomyelitis Treatment

Abstract Chitosan/polyvinylpyrrolidone (CH/PVP) scaffolds incorporating varying concentrations of dicalcium silicate (CS) particles − 0, 5, and 15 wt% (the corresponding codes CS0/CH: PVP, CS5/CH: PVP, and CS15/CH: PVP, respectively) - were fabricated using the freeze-drying technique to control their physicochemical properties, biocompatibility, drug release profile, and antimicrobial activity. Different analytical techniques were used, such as Transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) to determine structural and compositional characteristics of either ceramic powder or scaffolds. In vitro bioactivity and biodegradation were evaluated using simulated body fluid (SBF) maintained at 37 °C. Scanning electron microscopy (SEM) images indicated extensive apatite formation on the CS15/CH: PVP scaffold, forming a dense mineralized layer on its surface. The impact of incorporating CS on drug release behavior was examined using gentamicin as a model antibiotic agent. Results showed that increasing CS content led to a significant decrease in the drug release rate, suggesting a sustained release profile. Cytotoxicity tests using the human fibroblast cell line BJ1 demonstrated that all scaffold formulations exhibited minimal toxicity and were comparable to the negative control. The antimicrobial effectiveness was tested against Bacillus subtilis , Staphylococcus aureus , Escherichia coli , Salmonella typhi , and Candida albicans , demonstrating the scaffolds’ broad-spectrum antibacterial and antifungal capabilities. Overall, the CS/CH: PVP scaffolds presented a multifunctional platform with potential for bone tissue regeneration and localized antibiotic delivery.