Centre for Advanced Macromolecular Design, ‡School of Chemical Engineering, and §School of Chemistry, The University of New South Wales , Sydney, New South Wales 2062, Australia.
ACS Appl Mater Interfaces. 2016 Jul 6;8(26):16622-30. doi: 10.1021/acsami.6b04805. Epub 2016 Jun 21.
While the shape effect of nanoparticles on cellular uptake has been frequently studied, no consistent conclusions are available currently. The controversy mainly focuses on the cellular uptake of elongated (i.e., filaments or rod-like micelles) as compared to spherical (i.e., micelles and vesicles) nanoparticles. So far, there is no clear trend that proposes the superiority of spherical or nonspherical nanoparticles with conflicting reports available in the literature. One of the reasons is that these few reports available deal with nanoparticles of different shapes, surface chemistries, stabilities, and aspects ratios. Here, we investigated the effect of the aspect ratio of cylindrical micelles on the cellular uptake by breast cancer cell lines MCF-7 and MDA-MB-231. Cylindrical micelles, also coined rod-like micelles, of various length were prepared using fructose-based block copolymers poly(1-O-methacryloyl-β-d-fructopyranose)-b-poly(methyl methacrylate). The critical water content, temperature, and stirring rate that trigger the morphological transition from spheres to rods of various aspect ratios were identified, allowing the generation of different kinetically trapping morphologies. High shear force as they are found with high stirring rates was observed to inhibit the formation of long rods. Rod-like micelles with length of 500-2000 nm were subsequently investigated toward their ability to translocate in breast cancer cells and penetrate into MCF-7 multicellular spheroid models. It was found that shorter rods were taken up at a higher rate than longer rods.
尽管纳米颗粒的形状效应对细胞摄取的影响已经被广泛研究，但目前尚无定论。争议主要集中在长形（即纤维或棒状胶束）与球形（即胶束和囊泡）纳米颗粒的细胞摄取方面。到目前为止，没有明显的趋势表明球形或非球形纳米颗粒具有优势，文献中存在相互矛盾的报道。原因之一是这些少数报道涉及不同形状、表面化学、稳定性和纵横比的纳米颗粒。在这里，我们研究了圆柱形胶束的纵横比对乳腺癌细胞系 MCF-7 和 MDA-MB-231 摄取的影响。使用基于果糖的嵌段共聚物聚（1-O-甲基丙烯酰基-β-D-呋喃糖）-b-聚（甲基丙烯酸甲酯）制备了各种长度的圆柱形胶束，也称为棒状胶束。确定了触发各种纵横比的球形到棒形形态转变的临界水含量、温度和搅拌速率，从而生成不同的动力学捕获形态。高剪切力（如高搅拌速率下观察到的）被发现会抑制长棒的形成。随后研究了长度为 500-2000nm 的棒状胶束在乳腺癌细胞中的迁移能力以及穿透 MCF-7 多细胞球体模型的能力。结果发现，较短的棒状胶束的摄取速度比长棒状胶束快。
