中文摘要：

目的制备载多柔比星的羧基化介孔二氧化硅纳米粒（MSN-COOH-DOX）,考察其体外释放行为和细胞毒性。方法采用共聚法制备羧基化介孔二氧化硅纳米粒（MSN-COOH）,应用透射电镜表征纳米粒的形态,小角X射线衍射确认介孔结构,氮气等温吸附进行比表面积分析（BET）和孔径,孔容积分析（BJH）。紫外可见分光光度法评价载药量、包封率及体外释放。采用MTT染色法,分析其对MCF-7细胞和Hela细胞的细胞毒性。结果纳米粒分布均一,平均粒径约80 nm（PDI〈0.2）,比表面积为657.9 m2.g-1,孔径为2.27 nm。药物的包封率和载药量分别为54.6%,19.7%。纳米粒经24 h水浴振荡释放达平衡,在pH 5.0释放介质中累积释放分数达到95%。空白纳米粒具有较低的细胞毒性,载药纳米粒对MCF-7细胞和Hela细胞的毒性与游离多柔比星（DOX）相当。结论共聚法制备杂化介孔二氧化硅纳米粒（MSN-COOH）,具有较高的药物包封率,其可作为抗癌药物DOX的载体,粒子能被摄取,而且能趋于完全释放,载药后可降低DOX的细胞毒性。

英文摘要：

OBJECTIVE To prepare doxorubicin-loaded carboxylic acid-functionalized mesoporous silica nanoparticles,and evaluate its in vitro release and cell toxicity.METHODS Carboxylic acid-functionalized mesoporous silica nanoparticles were obtained by copolymerization methods.The nanoparticles morphology was examined by transmission electron microscope.The mesoporous structure was confirmed by small angle X-ray diffraction.And nitrogen adsorption techniques were used to characterize the specific surface area（BET） and pore size,and pore volume（BJH）.The encapsulation efficiency,drug loading rate and in vitro cumulative release rate were evaluated by UV-Vis spectrophotometry.The cytotoxicity of nanoparticles against MCF-7 cells and Hela cells was identified by MTT.RESULTS The distribution of the nanoparticles was uniform.The average particle size was 80 nm（PDI0.2）,the surface area was 657.9 m2·g-1,and the pore size was 2.27 nm.The encapsulation efficiency and drug loading rate were 54.6% and 19.7%,respectively.The drug release of the delivery system reached equilibrium after being shaken in water bath for 24 h.The cumulative release rate was around 95% in PBS（pH 5.0）.The nanoparticles had no cytotoxicity.The drug-loaded nanoparticles had equivalent cytotoxicity against MCF-7 cells and Hela cells with free doxorubicin.CONCLUSION Carboxylic acid-functionalized mesoporous silica nanoparticles with high drug encapsulation efficiency can be used as the carrier of anticancer drug doxorubicin in order to reduce the cytotoxicity.