Phytofabrication of silver nanoparticles using Sinapsis alba: Characterization, bioactivity evaluation and nanohydrogel formulation for wound healing applications

There has been increasing interest in wound dressings that deliver therapeutic agents to enhance healing and mitigate infection. This study aimed to formulate a nanohydrogel by incorporating phytosynthesized silver nanoparticles (AgNPs) derived from Sinapsis alba (SA) and to evaluate its in vivo wound-healing potential. Characterization of SA AgNPs by Ultraviolet-Visible spectrophotometry (UV-Vis) showed a prominent peak at 415 nm. Fourier Transform Infrared (FT-IR) analysis revealed that bioactive molecules of the SA extract are crucial for reduction and stabilization. X-ray diffraction spectroscopy (XRD) validated a face-centred cubic structure with a mean crystalline size of 15.36 nm. Field Emission - Scanning electron microscopy (FE-SEM) visuals confirmed spherical-shaped nanoparticles (19.4 nm). Antibacterial assay showed varying zones of inhibition (ZOI: 10.6–22.3 mm; MIC and MBC: 16 and 128 μg/ml). Antioxidant assay showed 92.6% radical neutralizing activity at 100 µg/ml. Brine shrimp assay using Artemia salina larvae affirmed the non-toxicity of AgNPs. A chitosan-SA AgNPs hydrogel (nanohydrogel) was formulated and evaluated for spreadability (245 ± 12.58%), in vitro drug release (63.3 ± 0.3% after 3 h), and swelling capacity (65.4%). Morphological analysis of the hydrogels by FE-SEM revealed a dense, porous microstructure embedded with nanoparticles. FT-IR analysis indicated efficient physical embedding and possible chemical binding between chitosan and SA AgNPs. The nanohydrogel showed no dermal toxicity and accelerated wound healing and closure by over 94% in Wistar albino rats, with histopathological evaluations confirming enhanced tissue regeneration. The remarkable antibacterial and antioxidant properties, wound-healing attributes, and non-toxic nature of nanohydrogels make them suitable candidates for developing phyto-nano-based wound healing agents.