pH及温度双重敏感性MCM-41/P(AA-co-NIPAAm)的制备和释药性能

通过微波辅助水热法制备了介孔分子筛 MCM-41，并将其与N-异丙基丙烯酰胺(NIPAAm)和丙烯酸(AA)原位聚合生成了一种新型的pH及温度双重敏感型复合材料MCM-41/P(AA-co-NIPAAm)，用XRD、N₂吸附-脱附、FT-IR、TGA对所得材料进行表征，结果表明合成了一种新型的复合材料。以氢氯噻嗪为模型药物进行载药性能测试并考察了此释药系统在不同pH及温度环境中的敏感释药行为。结果显示：MCM-41/P(AA-co-NIPAAm)复合材料的载药量达45.8%，并且通过改变环境体系的pH及温度可以有效控制药物的释放。复合材料在肠道靶向给药方面有一定的应用潜力。

Preparation and drug release of pH and temperature sensitive MCM-41/P (AA-co-NIPAAm)

Mesoporous silica materials with such advantages as high surface area,large pore volume,uniform porosity,stable aqueous dispersion,excellent biocompatibility,non-toxic properties,and the capability to be functionalized with different organic groups could be prepared.Such materials have the basic conditions for drug delivery due to the above advantages.In addition,in biomedical applications,smart intelligent hydrogels can be used for encapsulation of enzymes,controlled drug release,etc.and is also a good drug-carrier material.Smart intelligent hydrogels composites with mesoporous materials with the characteristics of the two materials can be made,and have a broad prospect in application.In this paper,mesoporous molecular sieve(MCM-41) was synthesized by the microwave method,and then composite material MCM-41/P(AA-co-NIPAAm) sensitive to pH value and temperature was synthesized by polymerization of MCM-41 with acrylic acid(AA) and N-isopropylacrylamide(NIPAAm) in situ.The materials were characterized by X-ray diffraction(XRD),nitrogen adsorption-desorption,Fourier transform infrared spectroscopy(FT-IR),and thermogravimetry analysis(TGA).It was found that a new polymer composite was synthesized.The polymer composite exhibited good sensitivities to both temperature and pH.Selecting hydrochlorothiazide as a model drug,the properties of drug loading and release behavior under different pH values and different temperatures were studied with ultraviolet spectrophotometry.The results showed that composite material MCM-41/P(AA-co-NIPAAm) had a high hydrochlorothiazide storage capacity of 45.8% and hydrochlorothiazide molecules were controlled released from the composite material by adjusting the temperature and pH of the environment.The material released drug faster in simulated intestinal fluid(pH=6.8).When the temperature was higher than 32℃,the release amount would decrease,and when the temperature was lower than 32℃,the release amount would increase significantly.Therefore,this novel MCM-41/P(AA-co-NIPAAm) composite has a potential application to targeted intestinal drug release.