2026/01/01 by Nada H. Aljarba, Hayfa Habes Almutairi, Nahla Alsayd Bouqellah +2 · 1 voice
Engineering · Materials Science · #Carbon and Quantum Dots Applications #Lignin and Wood Chemistry #Magnesium Oxide Properties and Applications
paper · doi:10.1515/gps-2025-0189
openalex publication_date 2026/01/01 · openalex created_date 2026/06/30 · openalex updated_date 2026/07/18
Abstract This study reports the sustainable valorization of walnut shells to synthesize lignin nanoparticles (LNPs) via a hydrothermal method, followed by doping with selenium and magnesium oxide (Se/MgO) to form a composite. The nanoparticles were characterized using ultraviolet–visible spectroscopy (UV–vis), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy coupled with energy-dispersive X-ray analysis (SEM–EDX). Morphological analysis indicated average sizes of 72 nm (LNPs) and 79 nm (Se/MgO-LNPs) via scanning electron microscopy, with transmission electron microscopy providing higher-resolution estimates of 33 nm and 37 nm, respectively. Bioactivity assessment demonstrated potent antimicrobial efficacy against bacteria ( Bacillus subtilis, Staphylococcus aureus, Klebsiella pneumoniae, Salmonella typhi ) and fungal ( Candida albicans, Candida tropicalis ) pathogens, with electron micrographs confirming ultrastructural damage. The antimicrobial mechanism involved significant inhibition of key metabolic enzymes, including phosphoglucose isomerase (PGI), pyruvate dehydrogenase (PDH), glucose-6-phosphate dehydrogenase (G6PDH), and nitrate reductase (NR), along with induction of protein leakage from cell membranes. Additionally, both nanoparticle types exhibited dose-dependent anti-biofilm activity against S. aureus and Escherichia coli and displayed notable antioxidant capacity in 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. In vitro cytotoxicity evaluation revealed selective anticancer activity against MCF-7 breast cancer cells, with half-maximal inhibitory concentration (IC 50 ) values of 116.8 μg/mL (LNPs) and 71.9 μg/mL (Se/MgO-LNPs). A favorable safety profile was indicated by higher IC 50 values against normal WI-38 human lung fibroblasts (448.1 μg/mL and 255.3 μg/mL, respectively).