Synthesis of cationic hydrogels with tunable physicochemical properties for antibacterial applications

Hydrogel materials are the preferred candidates for antimicrobial materials due to their high water absorption, superior biocompatibility and structural diversity. In this work, we present for the first time that diamine-alkyl and 1,3-dibromo-2-propanol can be rapidly cross-linked to prepare a series of new cationic polymer gels by polycondensation reactions under a strongly alkaline environment. The presence of C N + bonds are demonstrated in the formation of dendritic structured polymers by XPS analysis. In addition, the physicochemical properties of b-PHIs hydrogels were evaluated and it was found that the variation of diamine alkyl chain length could modulate the storage modulus, water uptake properties, thermal stability and zeta-potential of the gels. The increase in hydroxyl content and the C N + /C C ratio is evidenced by the elevated water absorption properties of the gels and the variations in zeta potential, respectively. In addition, the antibacterial performance evaluation showed that gels had good antibacterial activity against S. aureus and E. coli , with antimicrobial rates of b-PHOI as high as 96% and 97%, respectively. This work pioneers a brand-new idea for the simple and rapid synthesis of branched cationic polymers with low cytotoxicity in the field of antimicrobial biomaterials and proceeds a new attempt in the directional modulation of the physical properties of the materials.