Lignin produced nano zinc oxide flower particles and their antimicrobial, antibiofilm, invitro anticancer activity and toxicity on seed germination

Abstract

Nanoscience is currently investigating the use of plant extracts to synthesize metal/metal oxide nanoparticles (NPs). This approach is extremely promising, offering many advantages over conventional methods. The current investigation deals with eco-friendly and cost-effective bio nanocomposites were prepared using lignin-fabricated zinc oxide (L-ZnO), which is recognized as a valuable compound in the treatment regime due to its unique physical and chemical properties. UV visible absorption peak for ZnONFs shows the maximum absorption at a wavelength of 375 nm. Microscopy techniques such as field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM) described precise morphological characteristics of nanoflowers. A TEM image shows flower-like structures, petal edges with 202.23 ± 23.41 nm in diameter, and 281.69 ± 49.04 nm in a length. A cell viability test performed on HepG2 cells shows a decrease in cell viability in proportion to the concentration of L-ZnONFs in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) with an IC₅₀ value of 135 ± 6.75 μg/mL. Fluorescence-Activated Cell Sorting (FACS) analyses using Annexin V confirmed that L-ZnONFs induced apoptosis in HepG2 cells. Antimicrobial results demonstrated that the synthesized L-ZnONFs were more effective against Gram-negative bacteria (E.coli, K.pneumoniae, and S.typi) than Gram-positive bacteria (C. diphtheriae). The L-ZnONFs also demonstrated significant anti-biofilm effects in C. diphtheriae. In addition, L-ZnONFs were assessed for their impact on germination and growth in Raphanus sativus (radish), emphasizing their possibility as sustainable agrochemicals. These verdicts demonstrated that L-ZnONFs modified with lignin possess anticancer, and antibacterial properties, and can be used for therapeutic and agriculture field.