非球形α-Fe2O3@聚合物复合纳米粒子形貌与细胞作用的关系及在药物输送中的应用

Compared to spherical nanoparticles, non-spherical nanoparticles have been demonstrated as unique properties in the field of drug carrier, including longer blood circulation times, lesser extent phagocytized by macrophages and higher accumulation in the tumors. However, the relationship between nonspherical-shaped nanoparticles morphology (including size and shape) and cell is still lack of unified understanding, and the effect of morphology on the drug delivery system is far from elucidated. Given the ease of synthesis, various shapes and excellent biocompatibility of α-Fe2O3, this program is planned to use α-Fe2O3 as template to fabricate a series of α-Fe2O3@polymer composite nanoparticles with different shape and surface properties via a combination of sol-gel and surface-initiated atom transfer radical polymerization. The effect of morphology and surface properties of the nonspherical-shaped composite nanoparticles on endocytosis efficiency, endocytic pathway and cytotoxicity with different types cells will be carefully investigated to indicate the relationship of interaction between morphology and cell. Also the anticancer drug carrier and gene carrier with different morphology will be fabricated using α-Fe2O3 nanoparticles as template via surface chemical modification. The effect of shape on drug delivery and gene transfection will be investigated to indicate the rule of interaction between morphology and drug delivery and gene transfection. It is expected that the present study could provide theoretical basis for designing specific morphology drugs and gene carrier and promote the use of non-spherical nanoparticles in the biomedical field.

与球形纳米粒子相比，非球形纳米粒子在载药领域表现出独特性能：如更长的血液循环时间、更低的巨噬细胞内吞率以及更高的肿瘤细胞摄入率等。然而，对非球形纳米粒子的形貌（尺寸和形状）与细胞相互作用的关系尚缺乏统一认识，其对药物输送的影响也远未被阐明。本项目拟：1）以具有制备简单、形貌丰富、生物相容性好等优势的α-Fe2O3纳米粒子为研究对象，通过溶胶-凝胶法结合表面引发原子转移自由基聚合的方法，制备具有不同形貌、不同表面性质的非球形α-Fe2O3@聚合物复合纳米粒子；2）系统研究其对不同类型细胞的內吞效率、內吞途径、细胞毒性等的影响，揭示其形貌与细胞相互作用关系的一般规律；3）在不同形貌α-Fe2O3@聚合物复合纳米粒子表面，通过化学修饰制备抗癌药物载体和基因载体，研究其形貌对药物输送和基因转染的影响，为设计特定形貌药物或基因载体提供理论依据，促进非球形纳米粒子在生物医药领域的实际应用。

与球形纳米粒子相比，非球形纳米粒子在载药领域表现出独特性能：如更长的血液循环时间、更低的巨噬细胞内吞率以及更高的肿瘤细胞摄入率等。然而，对非球形纳米粒子的形貌（尺寸和形状）与细胞相互作用的关系尚缺乏统一认识，其对药物输送的影响也远未被阐明。本项以具有制备简单、形貌丰富、生物相容性好等优势的α-Fe2O3纳米粒子为研究对象，利用表面修饰的方法分别制备了不同形貌的荧光纳米粒子和基因载体。首先，利用经典的水热法制备得到纺锤形、椭球形和类球形三种形貌的α-Fe2O3纳米粒子，通过溶胶-凝胶法在其表面修饰具有聚集诱导发光效应(AIE)的SiO2薄层，得到了不同形貌的荧光纳米粒子。粒径和zeta电位测试表明，三种形貌的荧光纳米粒子具有相近的尺寸和电位。荧光光谱实验证明，三种荧光纳米粒子均具有较好的光稳定性，可用于较长时间的细胞成像。选取荧光强度相近的三种荧光纳米粒子分别与宫颈癌细胞(Hela cells)共同孵育，利用共聚焦显微成像技术结合图像处理软件Image J，考察了纳米粒子的形貌对其进入细胞速率的影响。实验结果表明：椭球形纳米粒子进入细胞的速率最快，其次为纺锤形，最后为类球形，这一实验结果初步表明纳米粒子的形貌对其进入细胞的速率具有一定的影响。在上述工作的基础上，以椭球形和纺锤形荧光纳米粒子为模板，通过表面修饰分别得到了表面修饰有聚乙烯亚胺（PEI）和三乙胺的四种基因载体。琼脂糖凝胶电泳阻滞实验证明了四种纳米基因载体对小牛胸腺DNA有着很好的结合能力。细胞毒性实验证明合成的纳米基因载体对Hela细胞有着较低的毒性，生物相容性较好，是一种很有潜力的纳米基因载体。通过本项目的研究，为设计特定形貌药物或基因载体提供理论依据，也期望该研究工作为解决目前纳米材料在植物领域基因转染存在的问题提供一定的理论指导。