咖啡酸改性明胶水凝胶制备及其抗氧化功能  

Preparation of caffeic acid-grafted gelatin hydrogel and its antioxidant function

作　　者：郝博雅 曾菲 温涛 孟洁[1] 许海燕[1] 刘健[1] HAO Bo-ya;ZENG Fei;WEN Tao;MENG Jie;XU Hai-yan;LIU Jian(Department of Biomedical Engineering, Institute of Basic Medical Sciences CAMS, School of Basic Medicine PUMC,Beijing 100005, China)

机构地区：[1]中国医学科学院基础医学研究所,北京协和医学院基础学院,生物医学工程学系,北京100005

出　　处：《基础医学与临床》2022年第7期1035-1041,共7页Basic and Clinical Medicine

基　　金：国家自然科学基金(32171343);中国医学科学院医学与健康科技创新工程(2021-I2M-1-006)。

摘　　要：目的制备咖啡酸改性明胶(CA-gel)水凝胶,研究不同接枝率对水凝胶理化性质的影响,初步评价其抗氧化性能。方法通过控制咖啡酸和明胶的投料比,制备不同接枝率的CA-gel,使用漆酶引发氧化交联反应,得到咖啡酸改性明胶水凝胶。使用高效液相色谱(HPLC)和核磁共振氢谱(^(1)H-NMR)表征CA-gel的分子结构;通过紫外-可见分光光度计测定咖啡酸接枝率;通过倒置试管法测定凝胶固化时间;使用微球压痕法测定其弹性模量;根据溶胀和降解前后质量变化计算溶胀率和降解速率;通过测定1,1-二苯基-2-2-三硝基苯肼自由基(DPPH·)溶液吸光度的变化计算其对DPPH自由基清除能力;使用细胞增殖-毒性检测(CCK-8)方法评价其细胞相容性及在过氧化氢环境中对成纤维细胞的保护作用。结果咖啡酸被接枝到明胶分子上,当接枝率分别为33.0μmol/g、61.8μmol/g、74.4μmol/g时,三种水凝胶的固化时间分别为33 min、42 min、47 min;弹性模量分别为7.2 kPa、29.4 kPa、34.5 kPa;溶胀率分别为896.5%、835.3%、803.9%;降解速率依次降低;对DPPH自由基清除能力分别为38.5%、41.9%、49.8%;具有良好的细胞相容性,并对过氧化氢环境中的成纤维细胞具有保护作用。结论CA-gel水凝胶获得了可调的固化时间、弹性模量、生物降解速率以及自由基清除能力,在高氧化应激微环境中对成纤维细胞有显著的保护作用。Objective To fabricate caffeic acid-grafted gelatin(CA-gel)hydrogels and investigate effects of the grafting ratios on the physicochemical properties of the hydrogels,and evaluate the antioxidant function of hydrogels.Methods CA-gel gelatin was synthesized by controlling the ratio of caffeic acid and gelatin,and the hydrogels were formed with laccase as the cross-linking agent.The molecular structure of caffeic acid-grafted gelatin was characterized by HPLC and ^(1)H-NMR.The grafting degree of caffeic acid was determined by UV-Vis spectrophotometer and the gelation time of hydrogel was determined by vial-tilting method.The elastic modulus was measured by microsphere indentation method.The swelling ratio and degradation rate of the hydrogel were calculated according to mass change before and after swelling and degradation,and the scavenging effect on DPPH radical(DPPH·)was determined by the change of absorbance of DPPH radical solution.Cell counting kit-8 was used to evaluate the cytotoxicityof the hydrogels and the protective effect on fibroblasts in high oxidative stress microenvironment.Results Caffeic acid was grafted onto gelatin molecules with following respective parameters:grafting degrees were 33.0μmol/g,61.8μmol/g and 74.4μmol/g,the gelation time was 33 min,42 min and 47 min,the swelling ratios of the hydrogels were 896.5%,835.3%and 803.9%,the elastic modulus of the hydrogels were 7.2 kPa,29.4 kPa and 34.5 kPa,and the scavenging effects on DPPH radical of the hydrogels were 38.5%,41.9%and 49.8%,respectively.In addition,the degradation rate decreased with the increase of grafting degree.The hydrogels were non-cytotoxic and displayed protective effect on the fibroblasts in the peroxide-existing environment.Conclusions CA-gel hydrogels have adjustable gelation time,biodegradation rate,elastic modulus and free radical scavenging activity and show a significant protective effect against fibroblasts in high oxidative stress microenvironment as well.

关 键 词：明胶水凝胶 咖啡酸 抗氧化 漆酶 

分 类 号：R318[医药卫生—生物医学工程]