壳聚糖改性明胶pH敏感型载药材料的制备及性能

Preparation and properties of chitosan modified gelatin as p H- sensitive drug- delivery material

选用低毒高效的交联剂京尼平(Gp)、交联明胶(G)和壳聚糖(C_s),制备p H敏感型复合高聚物载药材料Poly G-C。研究了明胶等电点(pI_G)、壳聚糖占比(Cs%)、壳聚糖脱乙酰度(D.D)及京尼平用量(Gp%)4个因素对Poly G-C等电点(pI_(PolyG-C))的影响;通过正交试验筛选了pI_(PolyG-C)=7.4时的最优配方;采用乳化交联法制备了Poly G-C负载的盐酸阿霉素微粒(Dox@Poly G-C),通过粒度分析仪测其平均粒径和分散度(PDI),并在p H=7.4和6.4的缓冲溶液中测试其释药性能。结果表明,制备pI_(PolyG-C)=7.4的最佳配方为:p IG=6.8;Cs%=60%;D.D=85%;Gp%=5%(w/w_(G+C));Zeta粒度分析仪测量Dox@Poly G-C平均粒径为257nm,分散度(PDI)为0.26;Dox@Poly G-C在p H=7.4和6.4的介质中的48h累计释药量分别为45%和90%,说明Poly G-C具有较好的pH敏感性。

PolyG - C, a kind of pH - sensitive drug - delivery material was prepared by chitosan modified gelatin via the cross - linking reaction of genipin. The effect of four factors on the isoeleetric point of PolyG - C （ plpolyG_ c ） were investigated, namely the isoelectric point of gelatin （piG ）, the ratio of chitosan to gelatin （Cs % ）, chitosan＇s deacetylation degree （D. D）and the dosage of genipin （ Gp % ）. Orthogonal experimental design was applied to screen the best conditions for the preparation of PolyG - C with the desired PIpolyG-C= 7. 4. PolyG - C particles loading adriamycin Were prepared using emulsion cross - linking method, its size was analyzed by Zeta particle size analyzer, the releasing ratio of adriamycin in pH = 7.4 and pH = 6. 4 were investigated. The results reveal that,the optimized conditions for PolyG - C with pIeolyG-C =7.4 are as follows：pIc =6. 8 ,Cs% =60% ,D. D =85% and Gp % = 5% （ Wcp/WG ＋C ）- The Dox@ PolyG - C particles show a narrow size distribution with an average diameter of 275nm and a PDI of 0. 26. Within 48 h, the drug releasing ratio are 45% and 90% in buffer solutions of pH = 7.4 and 6.4 respectively. This result indicates that, PolyG- C has good pH- sensitive performance.