Medical importance and pharmacokinetics of gold nanoparticles in the human body

Gold nanoparticles (AuNPs) have emerged as versatile nanocarriers with promising potential in therapeutic applications due to their tunable physicochemical properties, ease of functionalization, and excellent biocompatibility. Recognized as one of the most extensively studied nanomaterials, AuNPs have demonstrated utility in cancer diagnostics, photothermal therapy, targeted drug delivery, biosensing, vaccine development, antimicrobial treatments, gene delivery, imaging-guided therapy, and skin care formulations. While much research has focused on their design, formulations, and medical applications, understanding their fate within the human body is equally crucial. The long-term fate of AuNPs within the human body remains not well understood, largely due to the widely accepted notion that their inert nature impedes biodegradation. This review discusses the synthesis and biomedical applications of AuNPs, with a primary focus on recent advances in understanding their pharmacokinetic behavior in the human body guided by growing insights into their biological interactions, biodistribution, clearance mechanisms, and the key factors influencing there in vivo dynamics.