Effective bio-activities of the metal nanoparticles mycosynthesized by the plants’ fungal endophytes

Abstract Fungal endophytes act as bio-nano factories and are favored over bacteria and plant extracts, as they secrete large quantities of proteins and enzymes, facilitating stable, efficient, and economic nanoparticle synthesis. This review highlights the advantages of plant-associated fungal endophytes as bio-factories for metal nanoparticles (MNPs) synthesis and critically examines the biological activities and potential applications of these MNPs in human health, food technology, and agriculture. Compared to chemical synthesis, biogenic MNPs are more resistant to aggregation due to the involvement of different biomolecules, including secondary metabolites, enzymes, and proteins, reducing the metal ions to form MNPs. Biosynthesis of MNPs by several fungal genera, such as Fusarium spp., Penicillium spp., and Aspergillus spp., enables alleviation of the undesirable cytotoxicity and increased stability. In the food industry, MNPs play substantial roles in inhibiting browning and preventing food contamination. In agriculture, they act as herbicides, fungicides, pesticides, and plant growth promoters. Field application trials of these MNPs are recommended before their manipulation as a control strategy. In medicine, MNPs behave as antimicrobials, drug-delivery, antioxidants, and anticancer agents. They are applied in ophthalmology to facilitate drug delivery onto the site of infection via the improvement of targeted delivery. MNPs have demonstrated anticancer potency against cancer cell lines; however, they may also display cytotoxicity against the normal cells, especially at small sizes. However, at low pH, release of Ag + ‏ ions from AgNPs increases, where such information may aid in reducing the toxicity of the AgNPs. Conjugation of MNPs and antimicrobials has shown synergistic efficacy against the microbial resistance compared to the antimicrobials alone, reducing the development of antimicrobial resistance and decreasing the duration and the dose requirements of antimicrobial treatments. Nevertheless, comprehensive toxicological, pharmacokinetic, environmental, field, and in vivo studies are required before widespread application. The novelty of this review lies in spotting the light on the useful role of fungal endophytes as bio-factories for MNPs biosynthesis and emphasizing the promising applications of these MNPs in human health, food technology, and sustainable agricultural disease management, while highlighting the challenges and research priorities required for their safe and effective translation from laboratory studies to practical applications.