Novel Antioxidant and Antibacterial Injectable Hydrogels Incorporating Clove Oil-Loaded Mesoporous Bioactive Glass Nanoparticles: A Promising Strategy for Enhanced Bone Regeneration.

Alginate (Alg)-gelatin (Gel)-xanthan gum (Xan) injectable hydrogels incorporating mesoporous bioactive glass nanoparticles (MBGNs) loaded with different concentrations of clove oil (MBGNs+CLV) were developed for bone regeneration applications. The hydrogels exhibited an interconnected network of pores, with their dimensions fulfilling the requirements for bone tissue engineering. MBGNs+CLV were successfully embedded within the Alg-Gel-Xan matrix. The presence of CLV in the hydrogel was proven by the total phenolic content (TPC), which was further correlated with the enhanced antioxidant activity, which increased with higher CLV concentrations. Simultaneously, the addition of MBGNs+CLV led to an increase of the hydrogel's Young's modulus, while maintaining its injectability and adhesion properties. Based on the CLV release profile, a burst release was followed by a sustained and controlled release, which was independent of the loaded CLV concentration. The drug release profiles were further correlated with the degradation study, revealing the possible mechanism of drug release. The MBGNs+CLV-based hydrogel possessed strong antibacterial properties and promoted MC3T3-E1 pre-osteoblast cell viability without altering cell morphology. In conclusion, our study highlights the potential of Alg-Gel-Xan containing MBGNs+CLV as an antioxidant injectable hydrogel with controlled and sustained CLV delivery, offering a promising strategy for stimulating bone regeneration and addressing bone infection and oxidative stress.