A Systematic Review of the Genotoxicity and Antigenotoxicity of Biologically Synthesized Metallic Nanomaterials: Are Green Nanoparticles Safe Enough for Clinical Marketing?

Background and objectives: Although studies have elucidated the significant biomedical potential of biogenic metallic nanoparticles (MNPs), it is very important to explore the hazards associated with the use of biogenic MNPs. Evidence indicates that genetic toxicity causes mutation, carcinogenesis, and cell death. Materials and Methods: Therefore, we systematically review original studies that investigated the genotoxic effect of biologically synthesized MNPs via in vitro and in vivo models. Articles were systematically collected by screening the literature published online in the following databases; Cochrane, Web of Science, PubMed, Scopus, Science Direct, ProQuest, and EBSCO. Results: Most of the studies were carried out on the MCF-7 cancer cell line and phytosynthesis was the general approach to MNP preparation in all studies. Fungi were the second most predominant resource applied for MNP synthesis. A total of 80.57% of the studies synthesized biogenic MNPs with sizes below 50 nm. The genotoxicity of Ag, Au, ZnO, TiO(2), Se, Cu, Pt, Zn, Ag-Au, CdS, Fe(3)O(4), Tb(2)O(3), and Si-Ag NPs was evaluated. AgNPs, prepared in 68.79% of studies, and AuNPs, prepared in 12.76%, were the two most predominant biogenic MNPs synthesized and evaluated in the included articles. Conclusions: Although several studies reported the antigenotoxic influence of biogenic MNPs, most of them reported biogenic MNP genotoxicity at specific concentrations and with a dose or time dependence. To the best of our knowledge, this is the first study to systematically evaluate the genotoxicity of biologically synthesized MNPs and provide a valuable summary of genotoxicity data. In conclusion, our study implied that the genotoxicity of biologically synthesized MNPs varies case-by-case and highly dependent on the synthesis parameters, biological source, applied assay, etc. The gathered data are required for the translation of these nanoproducts from research laboratories to the clinical market.