载药果胶基纳米粒子体外HepG2肝癌细胞的靶向性研究

In vitro Evaluation of Pectin Nanoparticles Targeting Effect for Hepatocellular Carcinoma Cells

具有良好的生物相容性且生物可降解天然多糖,一直作为药物传递体系,具有如下优点:可延长药物的生物半衰期,减轻药物的毒副作用.本实验旨在制备一种果胶基载5-氟脲嘧啶(5-Fluorouracil,5-FU)纳米粒子(P-5-FU)载药系统,探讨果胶基纳米载药体系本身带有大量的半乳糖残基这种天然靶头对人肝癌细胞HepG2的靶向效果.MTT法测定载药果胶基纳米粒子对HepG2和A549细胞的增殖抑制作用,MTT结果显示P-5-FU对HepG2细胞的增殖具有明显抑制作用,呈剂量依赖性,且作用较5-FU强;而P-5-FU对A549细胞增殖亦有明显抑制作用,呈剂量依赖性,但与5-FU相比无明显差别;高效液相色谱法(HPLC)对两种细胞对载药纳米粒子的摄取情况和靶向性进行了测定.细胞摄取结果显示HepG2细胞对P-5-FU的摄取量较5-FU明显增多,而A549细胞对P-5-FU和5-FU的摄取量没有明显的差别.半乳糖饱和ASGPR结合位点后两种细胞对P-5-FU和5-FU的摄取量都没有明显的差别.结果表明果胶基纳米载药粒子可特异性靶向高表达的细胞.

Natural polysaccharide with good biocompatibility and biodegradability is always used as drug delivery system which offered numerous advantages, including reducing sideeffects, prolonging duration time, retaining drug bioactivity, and thus improving the thera- peutic efficiency. This study aimed to propose a targeting human hepatocellular carcinoma cells （HepG2） drug delivery system based on pectin nanoparticles whose chains have a large number of galactose residues and evaluate their targeting effect on HepG2 cells. Cytotoxicity study（MTY） in HepG2 and A549 cell lines demonstrates that the resulting 5-fluorouracil （5-FU）-loaded nanoparticles are more potent in killing cancer cells with over-expressed asialoglycoprotein receptor （ASGPR） on their surface, compared to free drug. While 5-FU- loaded nanoparticles can also inhibit the proliferation of A549 cells in a dosedependent way, but there is no significant difference compared with free 5-FU. Cellular uptake of 5-FU and P-5-FU by HepG2, A549 cells was detected by High Performance Liquid Chromatography （HPLC）. The HPLC results illustrate that the HepG-2 ceils can uptake more P-5-FU than free 5-FU, while co-incubated with galactose the HepG-2 cells has a relatively low uptake rate compared with P-5-FU and was closely comparable to that of free 5-FU. But the amount of 5-FU and P-5-FU in A549 cells was almost the same, when co-incubated with galactose for 2h the amount of uptake of the two cell line also has no significant difference. The resuhs indicate that the additional galactose competes with the “ galactose residues” in the pectin-based nanoparticles for binding to HepG2 cells, thus affects signifi- cantly the targeting efficacy of nanoparticles. However, no obvious difference was observed for A549 ceils under the same condition. The overall results confirm the targeting efficacy of pectin-based nanoparticles towards HepG2 cells.