功能化修饰纳米纤维素的结肠靶向给药载体

 纳米纤维素（cellulose nanocrystals，CNCs）具有优异的生物理化性能，可作为一种理想的新型药物载体。以马来酸酐酯化纳米纤维素（MA-CNCs）为载体，通过酯化反应进一步引入氨基酸连接臂，再与妥舒沙星（TFLX）偶联，得到新型妥舒沙星-氨基酸-马来酸酐酯化纳米纤维素药物轭合物（TFLX-A-MA-CNCs）。采用傅里叶变换红外光谱仪（FTIR）表征技术验证了妥舒沙星与马来酸酐酯化纤维素成功偶联。场发射扫描电镜（FE-SEM）观察发现MA-CNCs 可以较好地包覆药物。对TFLX-A-MACNCs药物轭合物在模拟胃液、小肠液和结肠液中的释药行为进行分析，结果表明MA-CNCs 载体对药物具有良好的包载性，且可实现结肠靶向释药。

Functionalized Cellulose Nanocrystals as a Carrier for Colon-targeted Drug Delivery System

With exquisite biological, physical and chemical properties, cellulose nanocrystals (CNCs) have been considered as an ideal drug carrier. A novel prodrug was prepared by the covalent attachment of the tosufloxacin tosylate (TFLX) onto the surface of maleated cellulose nanocrystals (MA-CNCs) with L-leucine as a spacer. The successful coupling of MA-CNCs and TFLX was detected by fourier transformation infrared spectroscopy (FTIR). The satisfactory coverage of MA- CNCs on TFLX is shown in FE- SEM micrographs. The release behaviors of TFLX- A- MA- CNCs in simulated gastric fluid (SGF), simulated intestinal fluid (SIF) and simulated colonic fluid (SCF) were investigated. The relationship between the accumulative drug release and the fluorescence response has been evaluated. The results show that the drug was efficiently entrapped by MA-CNCs carrier and presents excellent behavior for colon specificity and may be considered as a potential material for a colon-specific drug delivery system.