Phytochemical Mediated CuO, ZnO and MgO Based Mono, Bi and Trimetallic Oxide Nanomaterials for Biological Applications

Abstract

Due to their unique physicochemical properties, metal oxide nanomaterials (MO NMs) have recently emerged as promising materials for various biological applications. However, effective utilization of MO NMs in biological applications is determined by synthetic conditions including optimal reaction parameters and synthesis methods. Phytochemical-mediated synthesis of MO NMs has a significant role in biological applications. In this study, one-pot greener technique was used for the synthesis of mono (CuO, ZnO, and MgO), bi (ZnO-CuO, MgO-CuO, and MgO- ZnO) and trimetallic (ZnO-MgO-CuO) NMs using the leaf extract of Artemisia abyssinica (LEAA). The physicochemical properties of biosynthesized MO NMs were characterized using TGA/DTA, FTIR, XRD, UV-visible, SEM, EDX, TEM, and SAED techniques. From the TGA/DTA results, the thermal stabilities of nanomaterials were determined. XRD analysis revealed the synthesis of pure CuO, ZnO, and MgO NPs and mixed phases ZnO-CuO, MgO-CuO, MgO-ZnO and ZnO-MgO-CuO nanocomposities (NCs) with average crystallite sizes ranging from 11-15 nm. FTIR analyses have shown the involvement of functional groups from LEAA during the synthesis of NMs. The optical properties of mono, bi and trimetallic oxide NMs were investigated using UV-visible spectroscopic analysis. The EDX analysis confirmed the presence of a predictable composition of the NMs. The SEM and TEM/HRTEM-SAED analysis revealed that the synthesized NMs have a spherical morphology and crystalline nature with average particle sizes ranging from 12-16 nm. In-vitro antioxidant activity analysis of synthesized MO NMs was studied using DPPH and FRAP assays. DPPH assay results indicated that all the synthesized MO NMs have radical scavenging activity ranging from 81-97% at 200 g/mL with respective IC50 of 2.08-7.76 g/mL. Likewise, the biosynthesized MO NMs have exhibited the ferric reducing antioxidant power (FRAP) with an absorbance of 1.312±0.012-1.964±0.003 at 200 g/mL. Antibacterial activity of biosynthesized MO NMs against two gram-negative (Pseudomonas aeruginosa and Escherichia coli) and two gram-positive (Staphylococcus aureus and Streptococcus pneumonia) bacterial strains were evaluated. As the result demonstrated MO NMs have the zone of inhibitions between 25±0.02-35±0.03 mm at 200 g/mL against the tested bacterial strains. Antifungal activity evaluations showed that all the synthesized MO NMs are active against pathogenic (Aspergillus flavus, Aspergillus niger and Candida albicans) fungal strains with inhibition zones 22±0.11-31±0.03 mm at 200 g/mL. Anticancer activity results of xviiZC, MC, MZ, and ZMC NPs showed promising cytotoxicity against MCF-7 cell lines with the respective IC50 values of 33.12, 35.24, 37.47, and 24.83 g/mL. Moreover, the in silico molecular docking simulation of tested MO NMs has shown strong binding affinity against amino acid residues of S. aureus dihydrofolate reductase (PDB: 2w9h), E. coli DNA gyrase B (PDB: 6F86) and estrogen receptor alpha (ERα; PDB: 5GS4). These findings suggested that the biosynthesized MO NMs could be promising antioxidant, antibacterial, antifungal and anticancer (particularly for breast cancer) therapeutic agents. However, the in-vivo biological efficacies of MO NMs would be recommended to ensure the clinical use of NMs.