This study is to fabricate hyaluronic acid (HyA) hydrogels under the neutral pH condition in order to minimize the degradation of HyA during the cross-linking reaction. Two kinds of HyA hydrogels (HPDM or HPEN), were prepared with 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methyl-morpholinium chloride (DMTMM) or 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)/N-hydroxysuccinimide (NHS) as cross-linking agents, respectively, in the presence of putrescine as a diamine. Amide bond formation of hydrogels in the presence of putrescine was confirmed by FT-IR analysis. The morphology and rheological property of the hydrogels were studied through a scanning electron microscope and a rheometer, respectively. The swelling property and the degradation behavior of the hydrogels were affected by the two kinds of cross-linking agents and the molar ratio of the putrescine/cross-linking agents. Cytocompatibility of these hydrogels on human dermal fibroblast was confirmed by MTT assay. In conclusion, the cross-linking efficiency and the biocompatibility of HPDM cross-linked by DMTMM were better than those of HPEN cross-linked by EDC/NHS.

본 연구는 히알루론산의 가교 반응 중 분해를 최소화하기 위해, 중성 pH 조건에서 히알루론산 하이드로젤을 제조하는 것이다. 가교 반응은 diamine인 putrescine의 존재 하에, 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methyl-morpholinium chloride(DMTMM) 및 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide(EDC)/N-hydroxysuccinimide(NHS)를 각각 가교제로 사용하여 2종류의 히알루론산 하이드로젤을 제조하였다(HPDM 및 HPEN). FTIR 분석을 통해 두 가교제 모두 putrescine의 존재 하에, 아마이드기를 형성했음을 확인하였다. 반응에 따른 하이드로젤의 형태 및 유변학적 특성을 주사전자현미경 및 레오미터를 통해 확인하였다. 제조된 하이드로젤의 팽윤 특성 및 분해 거동은 가교제의 종류 및 putrescine/가교제의 몰비에 직접적인 영향을 받았다. 하이드로젤에서의 인체 섬유아세포에 대한 세포 적합성은 MTT assay를 통해 확인하였다. 결론적으로, DMTMM으로 가교한 HPDM의 가교 효율 및 생체 적합성이 EDC/NHS으로 가교한 HPEN 보다 더 우수하였다.

Keywords: neutral pH condition, putrescine, hyaluronic acid, 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methyl-morpholinium chloride, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide.