Effect of Curcumin-adsorbed ZnO Nanoparticles on the Physical, Mechanical, and Antibacterial Properties of Κ-carrageenan Hydrogels

This study investigates the impact of curcumin-adsorbed ZnO nanoparticles (C-ZnO NPs) on the physical, mechanical, and antibacterial properties of κ-carrageenan hydrogels. Microstructure analysis using SEM revealed that ZnO NPs formed needle-like structures, providing a large surface area for curcumin adsorption, with an average length of 377.24 nm and width of 46.09 nm. Functional group analysis using FTIR spectroscopy indicated successful curcumin adsorption on ZnO NPs. X-ray Diffraction (XRD) analysis showed no significant impact of curcumin on the crystallinity of ZnO NPs. UV-Vis spectroscopy results confirmed the formation of NPs with characteristic absorption peaks. Swelling analysis revealed that κ-carrageenan hydrogels exhibited a swelling rate of 1987.05 ± 8.28%, while C-ZnO loaded hydrogels showed a decreased swelling rate of 1705.01 ± 2.5%. Equilibrium water content analysis indicated that C-ZnO loaded hydrogels had a slightly lower water absorption capacity than hydrogels without NPs. Mechanical strength tests showed that C-ZnO loaded hydrogels had a significantly higher Young's modulus (0.25353 MPa) compared to κ-carrageenan hydrogels (0.07157 MPa). Drug release and kinetic modeling using the Hixson Crowell model best described the release behavior of C-ZnO from the hydrogels across various pH levels. Cell viability studies showed high viability for both hydrogel types, indicating their potential as biocompatible materials. Antibacterial tests demonstrated the effective bacteriostatic ability of C-ZnO loaded hydrogels against E. coli and S. aureus.