Effect of quasi-cryogelation on antimicrobialproperties of cerium-doped biopolymer films.

This study examines how cryogelation affects sodium alginate films crosslinked with cerium nitrate by comparing two types: AlgCe³⁺ and cryogelated QuasiAlgCe³⁺. The films were prepared by dissolving sodium alginate in water, then crosslinking with cerium nitrate for 12 hours at room temperature, and QuasiAlgCe³⁺, adding a freeze-thaw step at - 21°C for 24 hours. FTIR spectroscopy, swelling behavior in different solutions, water vapor transmission rate (WVTR), and UV-Vis absorbance characteristics were used to examine the physical and chemical structure of the films. Swelling tests revealed QuasiAlgCe³⁺ absorbed more water—reaching 115% in isotonic sodium chloride solution and 98% in deionized water—compared to AlgCe³⁺, and its WVTR was higher at 2614.15 g/day·m² versus AlgCe³⁺'s 1392.94 g/day·m², suggesting a more porous structure. However, when placed in PBS solution, they began to degrade and completely broke down in less than 15 minutes. UV-Vis results show AlgCe³⁺ is clearer above 300 nm, making it better for transparent uses like bandages, while QuasiAlgCe³⁺ blocks more UV light, which is better for protective coating applications. Overall, QuasiAlgCe³⁺ is more suited for moisture-regulating and UV-protective applications, like wound dressing.