A critical review of in vitro and in vivo biomedical applications of gold nanoparticles: From toxicology to cancer therapy.

Due to their unique and fascinating physicochemical properties, gold nanoparticles (AuNPs) are frequently used in the biomedical field including drug delivery, cancer therapy, biosensor, bioimaging, gene therapy, tissue engineering and antibacterial applications. Their superior properties such as high biocompatibility with living organisms, stability, SPR properties, small size, large surface area, adjustable stability, easy synthesizability and surface modification have increased the success of AuNPs in nanomedicine applications. AuNPs, which can be synthesized by many methods, can be easily adjusted in size and shape. Various mechanisms are being proposed to increase the affinity of functional group-bearing AuNPs to biomolecules and turn them into effective drug delivery systems with improved specificity. Among other metallic nanoparticles, AuNPs have great potential to be used in bio-imaging field. Considering the superior properties of AuNPs and controllable interactions with different biomolecules, AuNPs can be used as biosensor platforms in various diagnostic processes. This review article will be focused on the recent advances in various biomedical applications of AuNPs including toxicity, cancer therapy, drug delivery, gene silencing, bio-imaging, tissue engineering, diagnostic applications, and antibacterial studies. It is concluded that clinical studies on AuNPs with expanded strategies will be witnessed in the coming years.