聚乳酸／双亲性葡聚糖中空纳米囊泡包载亲水性药物及释放

亲水性药物包载是缓释纳米微粒制备的难点，通过共透析胆固醇改性葡聚糖和聚乳酸得到表面多糖修饰的中空纳米囊泡，在透析过程中以氯化钆溶液代替水相，所得纳米囊通过透射电子显微镜观察和热失重分析测试，证明氯化钆可包载于中空纳米囊泡的亲水性内核，且在纳米囊泡壁形成微孔道．将此纳米囊对亲水性药物头孢拉定反透析，药物通过微孔道扩散进入内核得到载药纳米囊．药物释放研究表明，纳米囊泡使亲水性药物持续释放24h以上，具有缓慢释放的特性．

Polylactic Acid/Amphiphilic Dextran Hollow Capsules for Hydrophilic Drug Loading and Release

Loading of hydrophilic drug is a challenge for the preparation of sustained release nanoparticles. In the present study, hollow capsules were prepared by dialysis-induced self-assembly of PDLLA and cholesterol-modified dextran. By replacing aqueous with GdCl3 solution during dialysis, GdCl3 was loaded into the aqueous core of hollow capsules and led to the formation of micro-channels on the wall of hollow capsules, which was confirmed by TEM observation and TG analysis. Those micro-channels facilitated the diffusion of hydrophilic drug into the aqueous core during reverse dialysis, and GdCl3 capsules against cephradine solution were then obtained. The release of cephradine from capsules lasted for over 24 h, demonstrating the sustained release feature of the drug-loaded capsules.