# Green and Ecofriendly Mycosynthesis of Nanocomposite Based on Zinc and Magnesium Oxide Nanoparticles Using Endophytic Sarocladium kiliense: Characterization, Anticancer Activity, Antimicrobial and Antibiofilm Activities

## TL;DR

A fungus is used to create eco-friendly zinc-magnesium nanoparticles that show promise in fighting cancer and bacteria.

## Contribution

A novel green method for synthesizing ZnO-MgO nanocomposites using a fungal strain with biomedical applications.

## Key findings

- The ZnO-MgO nanocomposite showed strong anticancer activity against MCF-7 cells with low toxicity to normal cells.
- The nanocomposite exhibited high antibacterial efficacy against Acinetobacter baumannii and Pseudomonas aeruginosa.
- Combining the nanocomposite with cefepime enhanced antibacterial effects, suggesting potential for drug resistance solutions.

## Abstract

Fungal species are increasingly recognized as efficient bio‐factories for the biosynthesis of nanoparticles with distinctive functionalities. In this study, zinc oxide‐magnesium oxide nanocomposite (ZnO‐MgO NCs) were biologically created employing the Sarocladium kiliense PV248633.1 fungal strain. Ultraviolet‐visible spectroscopy confirmed nanoparticle formation through characteristic absorption peaks, while Fourier‐transform infrared spectroscopy identified functional groups associated with metal‐oxygen bonds. Also, the nanoparticle size and surface characteristics Transmission electron microscopy and dynamic light scattering analyzes revealed an average particle size of 35 nm. Biological assessments demonstrate potent antitumor activity (IC₅₀ = 78.1 µg/mL) against MCF‐7 breast cancer cells, alongside minimal cytotoxicity against normal WI‐38 cells (IC₅₀ = 218.7 µg/mL), indicating selective toxicity. Antibacterial evaluations showed particularly high efficacy against Acinetobacter baumannii and Pseudomonas aeruginosa occasionally surpassing the performance of cefepime. Dose‐dependent antimicrobial activity was confirmed through well diffusion and broth microdilution techniques, with minimum inhibitory concentrations highlighting strong bactericidal potential. Biofilm inhibition assays revealed strain‐specific responses, with A. baumannii being the most susceptible. Furthermore, the synergistic combination of the biosynthesized nanocomposite with cefepime enhanced antibacterial outcomes against selected isolates, suggesting potential for addressing drug resistance. Overall, the mycogenic ZnO‐MgO NCs synthesized from S. kiliense exhibited substantial anticancer, antibacterial, and antibiofilm properties, locating this nanocomposite as a promising candidate for biomedical purposes.

Biosynthesis and multifunctional activities of ZnO–MgO nanocomposites using Sarocladium kiliense extract. The fungal extract of S. kiliense was utilized for the green synthesis of ZnO–MgO nanocomposites (NCs) using zinc nitrate and magnesium nitrate as precursors. The obtained NCs were characterized by UV–Vis, TEM, DLS, and XRD analyzes, confirming nanosized crystalline structures. The biosynthesized ZnO–MgO NCs exhibited potent antimicrobial, antibiofilm, and anticancer activities, suggesting their potential application in biomedical and pharmaceutical fields.