SILVER NANOPARTICLES (AGNPS): ADVANCES IN SYNTHESIS, CHARACTERIZATION, BIOMEDICAL APPLICATIONS, AND SAFETY CHALLENGES

Silver nanoparticles (AgNPs) have emerged as multifunctional nanomaterials with remarkable physicochemical and biological properties, making them suitable for biomedical, environmental, and industrial applications. AgNPs exhibit potent antimicrobial, antiviral, anti-inflammatory, and anticancer activities that are largely size-, shape-, and surface-dependent. Recent advances in synthesis methodologies, including physical, chemical, and green/biological approaches, enable precise control over particle morphology, surface functionalization, and biocompatibility. Characterization techniques such as TEM, SEM, DLS, XRD, FTIR, and ICP-MS are crucial to correlate physicochemical properties with biological outcomes. Mechanistic studies reveal that AgNPs disrupt microbial membranes, generate reactive oxygen species (ROS), release Ag⁺ ions, and interfere with cellular proteins and nucleic acids, resulting in cell death. Biomedical applications include wound healing, drug delivery, antimicrobial coatings, cancer therapy, and diagnostics. Despite the promising therapeutic potential, concerns regarding cytotoxicity, organ accumulation, environmental impact, and regulatory compliance remain critical. Strategies such as green synthesis, surface functionalization, controlled release, and safer-by-design approaches are under investigation to enhance efficacy while minimizing toxicity. This review provides an in-depth discussion of synthesis, characterization, biological mechanisms, biomedical applications, toxicity, regulatory challenges, and future perspectives, highlighting the translational potential of AgNPs.