Fatemeh Norouzi

Background: Taurine is a bioactive amino acid that has great potential for wound healing, but it struggles with poor skin penetration and quick clearance. This study aimed to develop taurine-loaded nanoliposomes (Nlp-Tau) to enable sustained local delivery and improve effectiveness. Methods: Nlp-Tau were prepared using thin-film hydration. We characterized them for size, charge, shape, encapsulation efficiency (EE%), loading efficiency (LE%), and in vitro release. Also, its biocompatibility on human foreskin fibroblasts (HFF) with a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT assay) has been assessed. In vitro wound healing potential was further evaluated using a scratch assay. Results: Optimized Nlp-Tau showed favorable properties, including an average hydrodynamic diameter of about 282 nm, a polydispersity index of 0.2, a strong negative zeta potential of −31.3 mV, and a spherical shape. However, transmission electron microscopy (TEM) images revealed diameters of about 142 nm and 194 nm for the drug-free and taurine-loaded particles, respectively. Additionally, EE% and LE% were 20% and 2.5%, respectively. In vitro release in PBS (pH 7.4) followed Higuchi kinetics, showing sustained release over 72 h. Nlp-Tau displayed excellent biocompatibility, with HFF viability significantly higher than other groups at concentrations up to 7 mg/mL. Importantly, in the scratch assay, Nlp-Tau treatment resulted in just 6.8% of the wound area remaining after 48 h, which outperformed free taurine at 10.7%. Conclusions: The Nlp-Tau system we developed offers a stable, biocompatible, and effective delivery method for sustained taurine release. It demonstrates greatly improved in vitro wound closure and shows strong potential for future wound care applications.

Foodborne diseases caused by microbial contamination, as a profound global health challenge, driving the search for natural antimicrobial compound. This study investigated the antimicrobial potential of Zataria multiflora essential oil ( Z. multiflora EO) encapsulated in alginate nanoparticles (Alg-EO), chitosan nanoparticles (Chi-EO), and nanoemulsions (NE-EO) against major foodborne pathogens: Escherichia coli ( E. coli ), Salmonella Typhimurium ( S. Typhimurium ), Pseudomonas aeruginosa ( P. aeruginosa ), and Staphylococcus aureus ( S. aureus ). The nanoformulations were prepared using spontaneous emulsification and ionic gelation techniques and subsequently characterized for size, zeta potential, and encapsulation efficiency via dynamic light scattering (DLS) and ATR-FTIR spectroscopy. Finally, the antibacterial activity of the nanoformulations was evaluated via the microdilution method. Results revealed that Chi-EO exhibited the smallest hydrodynamic diameter (129 nm) and highest negative zeta potential (− 37 mV), whereas Alg-EO and NE-EO measured 152 nm (− 28 mV) and 144 nm (24 mV), respectively. Notably, Chi-EO demonstrated strongest antimicrobial efficacy, with the lowest IC50 values against S. aureus (321 μg/mL), S. Typhimurium (460 μg/mL), E. coli (367 μg/mL), and P. aeruginosa (504 μg/mL). These findings highlight chitosan nanoparticles serve as an efficient delivery system for Z. multiflora EO, offering a natural and potent approach to improving food safety and extending shelf life.