Castillo Matias, Ebensperger Roberto, Wirtz Denis, Walczak Magdalena, Hurtado Daniel E, Celedon Alfredo
Department of Mechanical and Metallurgical Engineering, Pontificia Universidad Católica de Chile, Vicuña Mackenna, 4860, Macul, Santiago, Chile.
J Biomed Mater Res B Appl Biomater. 2014 Nov;102(8):1779-85. doi: 10.1002/jbm.b.33167. Epub 2014 Apr 3.
The mechanical response of the cytoplasm was investigated by the intracellular implantation of magnetic nanorods and exposure to low-frequency rotatory magnetic fields. Nanorods (Pt-Ni, ∼200 nm diameter) fabricated by electrodeposition in templates of porous alumina with lengths of approximately 2 and 5 µm were inserted into NIH/3T3 fibroblasts and manipulated with a rotational magnetic field. Nanorod rotation was observed only for torques greater than 3.0 × 10(-16) Nm, suggesting a Bingham-type behavior of the cytoplasm. Higher torques produced considerable deformation of the intracellular material. The cell nucleus and cell membrane were significantly deformed by nanorods actuated by 4.5 × 10(-15) Nm torques. Our results demonstrate that nanorods under magnetic fields are an effective tool to mechanically probe the intracellular environment. We envision that our findings may contribute to the noninvasive and direct mechanical characterization of the cytoplasm.
通过在细胞内植入磁性纳米棒并施加低频旋转磁场来研究细胞质的力学响应。将通过在多孔氧化铝模板中电沉积制备的直径约200nm、长度约2和5μm的纳米棒（Pt-Ni）插入NIH/3T3成纤维细胞中，并用旋转磁场进行操控。仅在扭矩大于3.0×10⁻¹⁶ Nm时观察到纳米棒旋转，这表明细胞质具有宾汉型行为。更高的扭矩会使细胞内物质产生相当大的变形。由4.5×10⁻¹⁵ Nm扭矩驱动的纳米棒会使细胞核和细胞膜发生显著变形。我们的结果表明，磁场作用下的纳米棒是机械探测细胞内环境的有效工具。我们设想，我们的发现可能有助于对细胞质进行无创且直接的力学表征。
