Enhanced anticancer activity of siRNA and drug codelivered by anionic biopolymer: overcoming electrostatic repulsion - supplementary information

Aim: To codeliver an anticancer drug (doxorubicin) and siRNA in the form of nanoparticles into CD44-overexpressing colon cancer cells (HT-29) using an anionic, amphiphilic biopolymer comprising modified hyaluronic acid (6-O-[3-hexadecyloxy-2-hydroxypropyl]-hyaluronic acid). Materials & methods: Characterization of nanoparticles was performed using dynamic light scattering, scanning electron microscopy, transmission electron microscopy, molecular docking, in vitro drug release and gel mobility assays. Detailed in vitro experiments, including a gene silencing study and western blot, were also performed. Results: A 69% knockdown of the target gene was observed, and western blot showed 5.7-fold downregulation of the target protein. The repulsive forces between siRNA and 6-O-(3-hexadecyloxy-2-hydroxypropyl)-hyaluronic acid were overcome by hydrogen bonding and hydrophobic interactions. Conclusion: We successfully codelivered a drug and siRNA by anionic vector.

研究目的：采用由修饰型透明质酸（6-O-[3-十六烷氧基-2-羟丙基]-透明质酸）构成的阴离子两亲生物聚合物，将抗癌药物多柔比星（doxorubicin）与小干扰RNA（siRNA）以纳米颗粒形式递送至CD44过表达结肠癌细胞（HT-29）中。
材料与方法：通过动态光散射、扫描电子显微镜、透射电子显微镜、分子对接、体外药物释放实验及凝胶迁移实验对纳米颗粒进行表征；同时开展了包含基因沉默实验与蛋白质印迹（western blot）在内的详细体外研究。
实验结果：靶基因的沉默效率达69%，蛋白质印迹结果显示靶蛋白的表达量下调5.7倍；siRNA与6-O-(3-十六烷氧基-2-羟丙基)-透明质酸之间的排斥作用力可通过氢键与疏水相互作用得以克服。
结论：本研究成功通过阴离子载体实现了药物与siRNA的共递送。