Antibacterial activity of a conventional hydrogel and a nanoparticle based hydrogel containing Satureja khuzestanica essential oil.

Bacterial infections are a major global health concern due to increasing antibiotic resistance and high mortality rates. Medicinal plants, such as Satureja khuzestanica essential oil (EO), offer a promising natural alternative for combating resistant pathogens. The bioactive composition of S. khuzestanica EO was analyzed using gas chromatography-mass spectrometry (GC-MS). Alginate/CarboxyMethyl Cellulose (CMC) and alginate nanoparticle/CMC hydrogels incorporating EO were formulated. Rheological properties were evaluated, and encapsulation efficiency was confirmed using Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR). The antibacterial efficacy of these formulations was assessed against Staphylococcus aureus and Pseudomonas aeruginosa. GC-MS identified carvacrol, thymol, gamma-terpinene, ortho-cymene, and limonene as the major bioactive compounds. Rheological analysis revealed that all formulations exhibited shear-thinning behavior, following the Carreau-Yasuda model. Notably, the alginate nanoparticle/CMC hydrogel containing EO (H-AlgNP/CMC-EO) demonstrated significantly enhanced antibacterial activity, achieving complete (100%) inhibition of S. aureus and P. aeruginosa growth, surpassing conventional hydrogels. The superior antimicrobial performance of H-AlgNP/CMC-EO highlights its potential as a novel therapeutic approach for combating bacterial infections, warranting further investigation in biomedical applications.