Myco-fabricated CuONPs and Ch-CuONPs conjugate mediated by the endophytic fungus Aspergillus fumigatus SM4 with in vitro antimicrobial, antibiofilm, antioxidant and anticancer activity

Abstract

The significant rise in antibiotic resistance has increased worries globally. In light of this situation, several investigations have been undertaken on biogenic nanoparticles and their conjugates to enhance their antibacterial and anticancer activities. The present work describes the myco-assisted biosynthesis of CuNPs using the marine-associated fungus Aspergillus fumigatus SM4. The biosynthesized CuNPs have been successfully coupled with chitosan. The Myco-CuNPs and Ch-CuNPs were characterized using UV, SEM, TEM, FTIR, XRD, and Zeta potential. Antimicrobial evaluation of both Myco-CuNPs and Ch-CuNPs indicated that CuNPs had substantial antibacterial efficacy, exceeding that of the crude extract, with inhibition rates of 78.25 % against Staphylococcus aureus and 70.25 % against Escherichia coli. The Ch-CuNPs showed potential biofilm inhibitory activity reached 52.62 % for E. coli and 51.52 % for S. aureus, respectively. The antifungal efficiency against Candida albicans demonstrated that CuNPs (45.36 %) surpassed the crude extract. However, nystatin emerged as the most effective antifungal drug (97.98 %). An antioxidant study by ABTS and DPPH tests revealed that Ch-CuNPs had enhanced antioxidant capacity relative to CuNPs and Vitamin C, with IC₅₀ values of 11.27 µg/mL and 16.15 µg/mL, respectively. The anticancer activity of these nanoparticles was assessed against the A549 cancer cell line, demonstrating that Ch-CuNPs exhibited greater selectivity with an IC₅₀ of 8.14 µg/mL, compared to CuNPs’ 10.35 µg/mL. The obtained results showed that CuNPs and Ch-CuNPs have antibacterial, antifungal, antioxidant, and anticancer effects, indicating its possible application in medicinal uses.