Chemical cross-linking on gelatin-hyaluronan loaded with hinokitiol for the preparation of guided tissue regeneration hydrogel membranes with antibacterial and biocompatible properties

Abstract The mechanical properties and structural stability of hydrogels and their performance in antidegradation can be enhanced by cross-linking them with N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC). However, residual EDC compromises the biocompatibility of cross-linked hydrogels and the formability of un-cross-linked hydrogels. In this study, a facile process for preparing hydrogel regenerative membranes exerting antibacterial effects and containing gelatin/hyaluronic acid (G/HA) through solution casting was proposed. The membranes were cross-linked with EDC (G/HA-Ec-0H) and impregnated with two concentrations of the antibacterial agent of hinokitiol (G/HA-Ec-2H and G/HA-Ec-4H). Amide bonds formed, and the rate of active amino acid fixation was higher than 90%, which was directly proportional to the degree of cross-linking. The G/HA-Ec-2H and G/HA-Ec-4H groups with hinokitiol showed good antibacterial properties. The rate of hydrogel degradation decreased, and the integrity of sample morphology was maintained at more than 80% for over 3 days in the immersion. Then, the hydrogel structures relaxed and disintegrated through a rapid degradation reaction within 24 h. The biocompatibility results showed that low concentrations of hinokitiol did not affect cell viability. Moreover, hydrogel membranes after 14 days of cell incubation showed good cell adhesion and proliferation. In summary, the membrane biostability of the cross-linked gelatin/hyaluronan hydrogels was enhanced by EDC at a biocompatible concentration, and the functionalized group of G/HA-Ec-2H shows potential as a biodegradable material for biocompatible tissue-guarded regeneration membranes with antibacterial properties.