Phytogenic Silver Nanoparticles as a Bioengineered Platform for Multifunctional Therapeutics: Synthesis, Characterization, and Biomedical Potential

The green synthesis of silver nanoparticles (SNPs) using medicinal plants provides a sustainable and eco-friendly approach to nanoparticle production with promising biomedical potential. In this study, Ricinus communis and Aloe barbadensis aqueous leaf extracts were employed as reducing and stabilizing agents to synthesize R. communis SNPs (RcSNPs) and A. barbadensis SNPs (AbSNPs). The nanoparticles were characterized using ultraviolet–visible spectroscopy, dynamic light scattering, Fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, and differential scanning calorimetry to evaluate their physicochemical and thermal properties. RcSNPs and AbSNPs were predominantly spherical, with average sizes of 15–20 nm and 23–28 nm, respectively, and exhibited stability up to ~90 °C. Biological evaluations demonstrated potent antimicrobial, antioxidant, anti-inflammatory, anti-tyrosinase, anticoagulant, and cytotoxic activities. Notably, RcSNPs and AbSNPs induced apoptosis through mitochondrial pathway modulation and showed superior cytotoxicity compared to crude plant extracts and several previously reported SNPs. These findings indicate that phytochemical-mediated SNPs not only provide a green route of synthesis but also exhibit multifunctional bioactivities, which may support their potential applications as antimicrobial, antioxidant, depigmenting, and anticancer agents in biomedical and pharmaceutical fields.