Biological Applications of Ball-Milled Synthesized Biochar-Zinc Oxide Nanocomposite Using Zea mays L

Abstract

Nanotechnology is one of the vital and quickly developing areas and has several uses in various commercial zones. Among the various types of metal oxide-based nanoparticles, zinc oxide nanoparticles (ZnO NPs) are frequently used because of their effective properties. The ZnO nanocomposites are risk-free and biodegradable biopolymers, and they are widely being applied in the biomedical and therapeutics fields. In the current study, the biochar-zinc oxide (MB-ZnO) nanocomposites were prepared using a solvent-free ball-milling technique. The prepared MB-ZnO nanocomposites were characterized through scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, X-ray powder diffraction (XRD), and thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), and ultraviolet-visible (UV) spectroscopy. The MB-ZnO particles were measured as 43 nm via the X-ray line broadening technique by applying the Scherrer equation at the highest peak of 36.36°. The FTIR spectroscope results confirmed MB-ZnO's formation. The band gap energy gap values of the MB-ZnO nanocomposites were calculated as 2.77 eV by using UV-Vis spectra. The MB-ZnO nanocomposites were tested in various in vitro biological assays, including biocompatibility assays against the macrophages and RBCs and the enzymes' inhibition potential assay against the protein kinase, alpha-amylase, cytotoxicity assays of the leishmanial parasites, anti-inflammatory activity, antifungal activity, and antioxidant activities. The maximum TAC (30.09%), TRP (36.29%), and DPPH radicals' scavenging potential (49.19%) were determined at the maximum dose of 200 µg/mL. Similarly, the maximum activity at the highest dose for the anti-inflammatory (76%), at 1000 μg/mL, alpha-amylase inhibition potential (45%), at 1000 μg/mL, antileishmanial activity (68%), at 100 μg/mL, and antifungal activity (73 ± 2.1%), at 19 mg/mL, was perceived, respectively. It did not cause any potential harm during the biocompatibility and cytotoxic assay and performed better during the anti-inflammatory and antioxidant assay. MB-ZnO caused moderate enzyme inhibition and was more effective against pathogenic fungus. The results of the current study indicated that MB-ZnO nanocomposites could be applied as effective catalysts in various processes. Moreover, this research provides valuable and the latest information to the readers and researchers working on biopolymers and nanocomposites.

Keywords: MB-ZnO nanocomposite; SEM; XRD; ball-milling; nanotechnology.

Figure 1

SEM images of pristine biochar (A) and MB-ZnO (B).

Figure 2

EDX spectra (A) and elemental analysis of MB-ZnO nanocomposites (B).

Figure 3

XRD patterns of MB-ZnO nanocomposites.

Figure 4

FTIR spectrum of MB-ZnO nanocomposites.

Figure 5

TGA of pure biochar (A) and MB-ZnO (B).

Figure 6

UV analysis of pure biochar (A), pure ZnO, and MB-ZnO (B).

Figure 7

Antioxidant potential of MB-ZnO.

Figure 8

Anti-inflammatory activity of MB-ZnO nanocomposites.

Figure 9

Inhibition potential of MB-ZnO nanocomposites against protein kinase (A) and alpha-amylase activities (B).

Figure 10

Biocompatibility against human RBCs and macrophages.

Figure 11

Antileishmanial potential of MB-ZnO at various concentration.

Figure 12

Antifungal potential of MB-ZnO nanocomposites. Fungal growth was observed in control (A), and at different concentrations of MB-ZnO nanocomposites including 6 mg/mL concentration (B), 12 mg/mL concentration (C) and 19 mg/mL concentration (D).