Conductivity enhancement by controlled percolation of inorganic salt in multiphase hexanoyl chitosan/polystyrene polymer blends

Hexanoyl chitosan and polystyrene blends are immiscible by the elucidation of the glass transition temperature （Tg） as well as the viscometric and morphological analyses. Selective localization of the lithium salt in hexanoyl chitosan phase as the percolation pathway enhanced the conductivity in the blends as compared to the neat hexanoyl chitosan. The ionic conductivity of a polymer electrolyte is described by σ = enp. Thus, estimation of charge carrier density （n） and mobility （μ） is important in order to assess the performance. In this work, these parameters are calculated using impedance spectroscopy and FTIR.

超声介导正己酰羧甲基壳聚糖载药纳米液滴对卵巢癌细胞的抑制作用

目的评价采用正己酰羧甲基壳聚糖制备相变型载阿霉素(DOX)纳米液滴的体外超声显像效果及抑制卵巢癌细胞生长的作用。方法将羧甲基壳聚糖与正己酸酐发生酰化反应合成正己酰羧甲基壳聚糖,采用声振乳化法制备正己酰羧甲基壳聚糖载药纳米液滴,表征其表面形态、粒径、电位;评价其体外超声显像效果,以紫外分光光度计测定药物包封率,采用CCK-8法检测卵巢癌细胞存活率,并进行统计学分析。结果成功制备正己酰羧甲基壳聚糖载药纳米液滴,镜下为大小均匀的球状物,平均粒径为(458.33±43.50)nm,包封率为(52.06±10.14)%。纳米液滴可增强超声显影效果。超声联合载药纳米液滴组的卵巢癌细胞存活率[(62.54±3.60)%]低于DOX组[(75.55±7.21)%]、载药纳米液滴组[(76.18±4.94)%]和超声组[(89.90±0.83)%],差异有统计学意义(P均<0.05)。结论超声联合正己酰羧甲基壳聚糖载药纳米液滴可有效抑制卵巢癌细胞生长,在临床诊疗中具有潜在应用价值。

己酰化乙二醇壳聚糖/泊洛沙姆复合水凝胶的制备及其药物缓释性能

为减少泊洛沙姆水凝胶的溶胶-凝胶转变温度对浓度的依赖性,以泊洛沙姆(P_(407))为基材,将己酰化乙二醇壳聚糖(HGC)与泊洛沙姆复合,制备了己酰化乙二醇壳聚糖/泊洛沙姆(HGC/P_(407))复合水凝胶,利用FTIR、SEM及试管反转法探讨了HGC/P_(407)复合水凝胶的性能,并利用紫外-可见分光光度计(UV-vis)对HGC/P_(407)复合水凝胶的体外药物缓释性能进行表征。结果表明,通过控制HGC的加入量,基于3%泊洛沙姆的HGC/P_(407)复合水凝胶即可发生溶胶-凝胶转变现象,并使HGC/P_(407)复合水凝胶的溶胶-凝胶转变温度处于32~37℃。HGC/P_(407)复合水凝胶具有高度孔隙率,孔隙之间相互连通,孔径大小处于10~90μm的范围之内。HGC/P_(407)复合水凝胶对抗癌药物吉西他滨的释药量达到82.4%~90.6%,缓释时间可达80 h左右。HGC/P_(407)复合水凝胶在可注射药物载体领域具有重要的应用前景。