载槲皮素PNIPAm纳米凝胶的制备及细胞学研究

Development and Cytological Study of PNIPAm-Based Nanogels Loaded with Quercetin

目的以聚(N-异丙基丙烯酰胺)(PNIPAm)凝胶为纳米载体,荷载抗肿瘤成分槲皮素,以增加药物对MCF-7细胞的毒性和细胞摄取。方法采用正交设计优化PNIPAm合成工艺,红外光谱进行结构确证;单因素试验优化载槲皮素纳米凝胶(Que-PNIPAm)处方及工艺,分别对粒径、表面形态、载药量进行表征并考察体外释放行为;CCK-8法考察纳米凝胶对MCF-7细胞的毒性;荧光倒置显微镜和流式细胞仪对纳米凝胶的MCF-7细胞摄取作用进行定性观察和定量测定;抑制剂法考察其细胞摄取机制。结果Que-PNIPAm的粒径为(166.1±2.87)nm,载药量为3.18%;电镜下纳米粒子呈类球形、粒径分布均匀;载药纳米凝胶对MCF-7细胞的抑制作用显著高于原药,且42℃下显示出更高的细胞摄取效率和抑制肿瘤细胞增殖活性;秋水仙素与2-去氧葡萄糖对细胞摄取有抑制作用。结论制备的载药纳米凝胶粒径小,具有温敏特性,能够显著增强药物被细胞摄取能力及肿瘤细胞毒性,MCF-7细胞对PNIPAm的摄取机制为微管蛋白途径。

OBJECTIVE To improve uptake and cytotoxicity of the drug on MCF-7 cells by developing a poly(N-isopropylacrylamide)(PNIPAm)nanogel for Quercetin(Que)METHODS The PNIPAm nanogel was optimized by an orthogonal design and its structure was confirmed by FT-IR.A single factor experiment was used to optimize the formulation of quercetin-loaded nanogel(Que-PNIPAm).The particle size,surface morphology and drug loading were characterized and the in vitro release behavior was investigated.Cytotoxicity of MCF-7 cells induced by Que-PNIPAm was investigated by CCK-8 method.The qualitative and quantitative cellular uptake studies were investigated by fluorescence microscope and flow cytometry,respectively.The mechanism of cellular uptake was investigated by the inhibitor method.RESULTS The particle size and drug loading of Que-PNIPAm were measured as(166.1±2.87)nm and 3.18%,respectively.Nanogel exhibited spherical morphology and uniform size distribution observed by electron microscopy.Compared to free Que,Que-PNIPAm significantly increased inhibition rate of MCF-7 cells.Que-PNIPAm also showed higher cell uptake efficiency and more effective antitumor activity at 42℃.Colchicine and 2-deoxyglucose have an inhibitory effect on MCF-7 cells uptake.CONCLUSION The prepared nanogel shows small particle size,thermosensitive property,which could significantly enhance the capacity of cellular uptake and tumor cytotoxicity.The mechanism of cellular uptake demonstrates tubulin is involved in the internalization of the nanogel into MCF-7 cells.