Antimicrobial activity and characterization of PVA/CMC hydrogels prepared with essential oil
Seyda Bayraktar, Buse Copur, Erdoğan Güneş, Ahmet Uysal, Ahmet Okudan
Abstract
This study provides a comprehensive analysis of PVA/CMC hydrogels, investigating their wettability, swelling behavior, antimicrobial efficacy, and surface morphology. Essential oils, including argan, clove, and aloe vera, were incorporated via the freeze-thaw method, significantly influencing the physicochemical properties of the hydrogels. The intrinsic hydrophobic nature of essential oils played a crucial role in modulating swelling characteristics, with PCO200 series exhibiting the highest swelling ratio due to lower crosslinking density, whereas clove oil-loaded hydrogels demonstrated the lowest swelling capacity, indicative of their enhanced hydrophobicity. Contact angle measurements further confirmed this trend, with PCO135 displaying the highest recorded value (83.20° ± 1.66°) and PCO235 following closely (79.86° ± 1.60°), underscoring the pronounced hydrophobic effect of clove oil compared to other formulations. SEM analysis revealed a well-defined macroporous structure in essential oil-containing hydrogels, with pore distribution and morphology varying depending on the oil type and concentration. FTIR spectroscopy identified distinct characteristic peaks corresponding to the functional groups of the incorporated oils, elucidating their molecular interactions within the hydrogel network. Antimicrobial analysis highlighted clove oil’s robust activity, with enhanced effects in specific formulations against bacteria such as Klebsiella pneumonia, Salmonella enteritidis, Pseudomonas aeruginosa, and Methicillin Resistant Staphylococcus aureus . These findings contribute to the growing body of knowledge on hydrogel-based delivery systems and highlight the potential of essential oil-modified hydrogels for wound dressing applications and the development of antimicrobial hydrogel formulations.