Pyo Nayoung, Tanaka Saaya, McNamee Cathy E, Kanda Yoichi, Fukumori Yoshinobu, Ichikawa Hideki, Higashitani Ko
Department of Chemical Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
Colloids Surf B Biointerfaces. 2006 Dec 1;53(2):278-87. doi: 10.1016/j.colsurfb.2006.09.020. Epub 2006 Oct 10.
We used the atomic force microscope to study how the cell type and the density of cells adsorbed at a substrate can affect the adhesion between a living cell and a model drug delivery system (DDS) carrier nano-particle. We used three different anchorage-dependent cells, i.e., a living mouse fibroblast cell (L929), a living human colon cancer cell (Caco2), and a living mouse malignant melanoma cell (B16F10). For the DDS model nano-particle, we used a silica colloid. In order to correlate the adhesion force with the cell types, the growth curve of the cells were determined with a haemocytometer. The shapes of the cells at the different stages were monitored by light microscopy, and the morphology of their surfaces obtained by tapping mode atomic force microscopy. Force measurements showed that the Caco2 cell bound little to a silica particle, regardless of the cell density. The L929 cell bound well to a silica particle for low and high cell densities. The B16F10 cell bound little to a silica particle for low cell densities, but bound well for high cell densities. AFM images showed that the L929 cell did not contain folds. The B16F10 cells, however, displayed folds in the cell surface for low cell densities, but no folds in the cell for high cell densities. As literature also reported that the Caco2 cell contains folds, these results suggested that cells with folds showed less adhesion to a silica particle than cells without folds. The presence of folds in the cell presumably decreased the number of sites on the cell that could hydrogen bond or undergo van der Waals binding with the silanol groups of the silica particle.
我们使用原子力显微镜来研究细胞类型以及吸附在基质上的细胞密度如何影响活细胞与模型药物递送系统（DDS）载体纳米颗粒之间的粘附。我们使用了三种不同的贴壁依赖性细胞，即活的小鼠成纤维细胞（L929）、活的人结肠癌细胞（Caco2）和活的小鼠恶性黑色素瘤细胞（B16F10）。对于DDS模型纳米颗粒，我们使用了硅胶。为了将粘附力与细胞类型相关联，使用血细胞计数器测定细胞的生长曲线。通过光学显微镜监测细胞在不同阶段的形状，并通过轻敲模式原子力显微镜获得其表面形态。力测量表明，无论细胞密度如何，Caco2细胞与硅胶颗粒的结合都很少。L929细胞在低细胞密度和高细胞密度下都能很好地与硅胶颗粒结合。B16F10细胞在低细胞密度下与硅胶颗粒的结合很少，但在高细胞密度下结合良好。原子力显微镜图像显示L929细胞没有褶皱。然而，B16F10细胞在低细胞密度下细胞表面有褶皱，但在高细胞密度下细胞没有褶皱。由于文献也报道Caco2细胞含有褶皱，这些结果表明有褶皱的细胞比没有褶皱的细胞对硅胶颗粒的粘附性更小。细胞中褶皱的存在可能减少了细胞上可以与硅胶颗粒的硅醇基团形成氢键或发生范德华结合的位点数量。
