Green synthesis of Multifunctional Zinc oxide Nanoparticles from Cordia myxa gum; and their Catalytic Reduction of Nitrophenol, Anticancer and Antimicrobial Activity.

In situ exfoliated natural polysaccharide Cordia myxa (CMX) is used to promote the utilization of zinc-oxide nanoparticles for eco-friendly catalytic hydrogenation of p-nitrophenol (p-NP) and microbial growth inhibition. Polysaccharide-mediated biosynthetic nanocomposite materials are interesting because they are cheap, green, and environmentally friendly. This study uses CMX gum as a bioreduction to produce multifunctional, environmentally friendly zinc-oxide nanocomposites (ZnO NPs). The process involves a low reaction time and temperature and utilizes CMX as a reducing and stabilizing agent. The structural, morphological, and optical properties of the CMX-ZnO nanocomposite were characterized. The biosynthetic CMX-ZnO NPs exhibited robust catalytic activity and recycling capacity for rapidly oxidizing hazardous p-NPs. The complete reduction of 4-NP to CMX-ZnO NPs in excess NaBH4 was achieved within 15 min, with recyclability and pseudo-first-order kinetics with a rate constant of 0.2571 min-1. Additionally, human colon cancer (HCT116) and 3T3L1 cell lines were remarkably sensitive to the cytotoxic effects of ZnO nanoparticles. CMX-ZnO NPs exhibited potent antibacterial properties against human pathogenic gram-positive and gram-negative bacteria (Bacillus, Salmonella, E. coli, and Pseudomonas aeruginosa) based on the zone of inhibition measured by the disc-diffusion method. The significant antibacterial activity of CMX-ZnO NPs can overcome the current limitations associated with removing water-soluble organic pollutants and microbiological contaminants for long-term environmental sustainability.

Tragacanth gum-based multifunctional hydrogels and green synthesis of their silver nanocomposites for drug delivery and inactivation of multidrug resistant bacteria.

This study investigated natural polymer-based stimuli-responsive hydrogels (TGIAVE) and their silver nanocomposites (TGIAVE-Ag). The hydrogels were composed of tragacanth gum, N-isopropyl acrylamide, and 2-(vinlyoxy) ethanol and were prepared via simple redox polymerization using N,N'-methylene-bis-acrylamide as a crosslinker and potassium persulfate as an initiator. The TGIAVE-Ag were synthesized via a green method involving an aqueous extract of Terminalia bellirica seeds. Structural, thermal, crystallinity, morphology, and size characteristics of the TGIAVE and TGIAVE-Ag were investigated by FTIR, UV-Vis, XRD, DSC, SEM, EDS, DLS, and TEM. To understand the physicochemical interaction and diffusion characteristics of TGIAVEs, network parameters such as zero-order, first-order, Hixson-Crowell, Higuchi, and Korsmeyer-Peppas values were calculated by assessing swelling data. TGIAVE hydrogels at pH 1.2 and 7.4 and temperatures of 25 and 37 °C may be used for time-dependent controlled release of 5-fluorouracil, an anticancer drug, TGIAVE-Ag may be applied for the inactivation of multidrug resistant (MDR) bacteria.