Design of Plant Oil-Based Cationic Hydrogels for Protein Encapsulation and Controlled Delivery

The development of sustainable multifunctional hydrogels with antibacterial activity and protein delivery capability is of great interest for biomedical applications. In this study, plant oil-derived cationic hydrogels were developed by UV-induced polymerization using acrylated methyl ricinoleate (AMR), a renewable monomer derived from castor oil, and 2-aminoethyl methacrylate (AEMA). The influence of hydrogel composition on morphology, pH-responsive swelling, antibacterial activity, cytocompatibility, and protein encapsulation behavior was investigated. FTIR and SEM analyses confirmed successful hydrogel formation and revealed composition-dependent structural differences. The swelling behavior was strongly influenced by pH and monomer ratio. The hydrogels exhibited significant antibacterial activity against Escherichia coli and Staphylococcus aureus while maintaining good cytocompatibility toward human umbilical vein endothelial (HUVEC) cells, with cell viability exceeding 80%. Bovine serum albumin (BSA) was used as a model protein to evaluate encapsulation and release properties. Protein encapsulation efficiency was found to depend strongly on crosslinking density, with lower crosslinking ratios leading to enhanced loading. Overall, the results demonstrate that combining a renewable plant oil-derived monomer with a cationic component enables the fabrication of sustainable hydrogels with tunable physicochemical and biological properties, highlighting their potential for wound healing and localized protein delivery applications.