In this study, we propose to synthesize NPs using plant extract containing active biomedical components, with the goal of obtaining NPs that inherit the biomedical activities of the plant. Herein, we report the synthesis of manganese dioxide nanoparticles (VBLE-MnO₂ NPs) using the leaves extract of Viola betonicifolia, in which the biological active plant’s secondary metabolites function as both reducing and capping agents. The synthesized NPs were successfully characterized with different spectroscopic techniques. The antibacterial, antifungal, and biofilm inhibition properties of the synthesized VBLE-MnO₂ NPs were further explored against a variety of bacteria (Gram-positive and Gram-negative) and mycological species. Additionally, their antioxidant ability against linoleic acid peroxidation inhibition, cytobiocompatibility with hMSC cells, and cytotoxicity against MCF-7 cells were investigated compared to leaves extract and chemically synthesized manganese dioxide NPs (CH-MnO₂ NPs). The results were demonstrated that the synthesized VBLE-MnO₂ NPs presented excellent antibacterial, antifungal, and biofilm inhibition performance against all the tested microbial species compared to plant leaves extract and CH-MnO₂ NPs. Moreover, they also exhibited significant antioxidant potential, which was comparable to the external standard (ascorbic acid); however, it was higher than plant leaves extract and CH-MnO₂ NPs. Furthermore, the synthesized CH-MnO₂ NPs displayed good cytobiocompatibility with hMSC cells compared to CH-MnO₂ NPs. The enhanced antioxidant, antibacterial, antifungal, and biofilm inhibition efficacy as compared to CH-MnO₂ NPs might be attributed to the synergistic effect of the VBLE-MnO₂ NPs’ physical properties and the adsorbed biologically active phytomolecules from the leaves extract of V. betonicifolia on their surface. Thus, our study establishes a novel ecologically acceptable route for nanomaterials’ fabrication with increased and/or extra medicinal functions derived from their herbal origins.

Background: The skin regulates body processes. When damaged, it is prone to breeding bacteria, causing inflammation and impeding wound healing. There is an urgent need for new dressings that can combat bacteria to aid in infectious wound repair. Methods: In this study, a curcumin-loaded nanocomposite hydrogel dressing (GelMA/AHA-Gel@Cur) with antibacterial properties and strong toughness was synthesized, designed to combine the modified gelatin-based hydrogel (GelMA/AHA) with curcumin-coated gelatin (Gel@Cur) nanoparticles to promote the healing of bacterial infection wounds. Under UV irradiation, methylacrylylated gelatin (GelMA) and aldehyaluronic acid (AHA) formed a composite network hydrogel through radical polymerization and Schiff base reaction. Meanwhile, the residual aldehyde group on the molecular chain of AHA securely locked Gel@Cur nanoparticles in the hydrogel network through Schiff base reaction. Results: The addition of Gel@Cur nanoparticles not only enhanced the hydrogel’s mechanical strength but also facilitated a sustained, gradual release of curcumin, endowing the composite hydrogel with robust antimicrobial capabilities. In an animal model of infected wounds, the composite hydrogel significantly improved wound closure, healing, and vascularization compared to the control group. Hemocompatibility tests confirmed the hydrogel’s safety, with a hemolysis ratio of just 0.45%. Histological evaluation following treatment with the composite hydrogel showed improved tissue architecture, increased collagen deposition, and regeneration of dermal gland structures. Conclusion: The GelMA/AHA-Gel@Cur composite hydrogel exhibits excellent mechanical properties, potent antimicrobial activity, and controlled drug release, along with superior cell and hemocompatibility. These characteristics make it a promising material for infected wound repair and a potential candidate for clinical skin regeneration applications.