EMERGING TRENDS IN THE SYNTHESIS AND THERAPEUTIC EVALUATION OF SILVER NANOPARTICLES

Avijit Bej*, Rakesh Kumar Sahu*, Ravindra Kumar, Aniked Kumar, Abhay Kumar Singh, Haroon Rashid, Niraj Kumar

Silver nanoparticles (AgNPs) have emerged as highly versatile agents in biomedical science due to their unique physicochemical properties, including a high surface-area-to-volume ratio and strong surface plasmon resonance. This review highlights recent advancements in the synthesis of AgNPs, emphasizing the crucial role of tailoring size typically between 1 and 100 nm—and diverse morphologies such as nanorods and nanoprisms to optimize localized surface plasmon resonance (LSPR). We examine the significant shift toward "green" synthesis methods utilizing extracts from plants, fungi, and bacteria, which serve as natural reducing and stabilizing agents to produce nanoparticles with enhanced biocompatibility and lower toxicity than traditional chemical routes. The review further evaluates the extensive therapeutic applications of AgNPs, focusing on their multi-directional antimicrobial mechanisms, such as DNA damage, protein disruption, and the induction of reactive oxygen species (ROS), which enable them to combat multi-drug-resistant pathogens and various viruses, including SARS-CoV-2. Beyond infection control, the integration of AgNPs into hydrogels and scaffolds demonstrates substantial efficacy in promoting keratinocyte proliferation for wound healing and stimulating osteoblast activity for bone regeneration. Additionally, we explore emerging roles in oncology through antiangiogenic and pro-apoptotic effects, and in metabolic health via the inhibition of glucose-regulating enzymes like alpha-amylase. Despite these promising trajectories, the review concludes by addressing critical challenges, including potential systemic toxicity and the need for rigorous regulatory frameworks to manage the environmental and biological impact of long-term silver accumulation.