Silver Nanoparticles (AgNPs) as a Double-Edged Sword: Synthesis, Factors Affecting, Mechanisms of Toxicity and Anticancer Potentials-An Updated Review till March 2025.

Silver nanoparticles (Ag-NPs) are widely utilized in cosmetics, healthcare, and antimicrobial products due to their potent antimicrobial and anticancer properties. However, their increasing use raises concerns about cytotoxic effects on human health and the environment. Ag-NPs interact with biological systems in a size-, dose-, and time-dependent manner, with particles smaller than 10 nm often exhibiting heightened toxicity. In vivo studies show their ability to cross the blood-brain barrier and accumulate in organs such as the liver, spleen, and brain. This review critically evaluates the cytotoxic mechanisms and anticancer therapeutic potential of Ag-NPs, presenting them as a double-edged sword. A comprehensive literature search was conducted on the PubMed, Scopus, Web of Science, etc. database for the period 2005-2025 using keywords including "Silver Nanoparticles AND anticancer," "tumor," and "cytotoxicity." The search yielded 1100 articles related to anticancer activity, 2879 on cytotoxicity, 460 on green-synthesized Ag-NPs tested for anticancer effects, and 3418 on green synthesis of AgNPs alone. The review discusses how physicochemical properties-such as size, shape, and surface chemistry-influence cytotoxicity through mechanisms like oxidative stress, mitochondrial damage, and DNA disruption. It also highlights recent advancements in Ag-NP synthesis and biomedical applications, underscoring the importance of balancing their therapeutic benefits against potential health risks.