水溶性壳聚糖纳米粒子的制备及其BSA载药性能

为了避免高分子量壳聚糖水溶性差以及增溶剂乙酸可能带来的负面作用，本文选择低分子量水溶性壳聚糖 (WSC)作研究对象，采用三聚磷酸(TPP)作交链剂制备不同WSC/TPP比率的WSC纳米粒子，并用于牛血清白蛋白 (BSA)的释放载体。经测得为球形形貌的纳米粒子空载和载药时粒径、Zeta电位分别在35～190 nm、35～42 mV。红外光谱及X–射线衍射证实了纳米粒子中WSC的氨基与TPP的磷酸基团发生了交联反应。纳米粒子载药性能试验表明在0.05～1 mg/mL范围内随着BSA浓度的增大，纳米粒子的载药量增加而负载率降低。体外释放实验表明水溶性壳聚糖纳米载体对蛋白质药物具有缓释特征。因此，水溶性壳聚糖有望成为新的载体应用于蛋白质药物的控制释放。

Preparation and characterization of water-soluble chitosan nanoparticles as BSA delivery system

In order to avoid the low solubility of high molecular weight chitosan in aqueous media and the disadvantages induced by acetic acid that is used usually as a solubilizer，water-soluble chitosan (WSC) was investigated. WSC nanoparticles (WSC NP) with various ratios of WSC/ tripolyphsphoric acid cross-linking agent were prepared based on ionic gelation，and were used to load bovine serum albumin (BSA) for release in vitro. Blank and BSA-loaded WSC nanoparticles were examined with diameter 35～190 nm，zeta potential 35～42 mV and spherical shape. FTIR and XRD confirmed tripolyphsphoric groups of tripolyphsphoric acid linked with amino groups of WSC in the nanoparticles. WSC NP loading studies showed that altering concentration of BSA from 0.05 to 1 mg/mL enhanced loading capacity of BSA but decreased loading efficiency simultaneously. Release studies in vitro suggested that WSC had the properties of controlled-release proteins delivery. These results indicate that WSC nanoparticles are promising carriers system for protein delivery.