Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
Phys Chem Chem Phys. 2019 Sep 21;21(35):18830-18838. doi: 10.1039/c9cp02935d. Epub 2019 Jul 19.
In biomedical technologies that use nanoparticles, the nanoparticles are often required to translocate across a cell membrane. Application of an external electric field has been used to increase the cell membrane permeability; however, damage to the cell is of great concern. Using a molecular dynamics simulation, we show that even under a weak external electric field that is lower than the membrane breakdown intensity, a cationic nanoparticle will directly translocate across a model cell membrane without membrane disruption. We then reveal its physical mechanism. At the contact interface between the nanoparticle and the cell membrane, the electric potential across the membrane is locally enhanced by superimposing the nanoparticle surface potential on the externally applied potential, resulting in its direct translocation. Our finding implies that, by controlling the nanoparticle-induced local enhancement of the membrane potential, the cellular delivery of nanoparticles via a non-endocytic and non-disruptive pathway can be realized.
在使用纳米粒子的生物医学技术中，纳米粒子通常需要穿过细胞膜。应用外部电场已被用于增加细胞膜的通透性；然而，对细胞的损伤是一个很大的关注点。通过分子动力学模拟，我们表明，即使在低于膜破裂强度的弱外部电场下，带正电荷的纳米粒子也会在不破坏细胞膜的情况下直接穿过模型细胞膜。然后我们揭示了它的物理机制。在纳米粒子和细胞膜的接触界面处，通过将纳米粒子表面电势叠加在外加电势上，膜间的电势会在局部增强，从而导致其直接转移。我们的发现意味着，可以通过控制纳米粒子诱导的膜电位局部增强，实现通过非内吞和非破坏途径将纳米粒子递送到细胞中。
