Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zurich , Zurich, Switzerland.
Nano Lett. 2015 Mar 11;15(3):1743-50. doi: 10.1021/nl504438z. Epub 2015 Feb 6.
From its invention in the 1970s, the patch clamp technique is the gold standard in electrophysiology research and drug screening because it is the only tool enabling accurate investigation of voltage-gated ion channels, which are responsible for action potentials. Because of its key role in drug screening, innovation efforts are being made to reduce its complexity toward more automated systems. While some of these new approaches are being adopted in pharmaceutical companies, conventional patch-clamp remains unmatched in fundamental research due to its versatility. Here, we merged the patch clamp and atomic force microscope (AFM) techniques, thus equipping the patch-clamp with the sensitive AFM force control. This was possible using the FluidFM, a force-controlled nanopipette based on microchanneled AFM cantilevers. First, the compatibility of the system with patch-clamp electronics and its ability to record the activity of voltage-gated ion channels in whole-cell configuration was demonstrated with sodium (NaV1.5) channels. Second, we showed the feasibility of simultaneous recording of membrane current and force development during contraction of isolated cardiomyocytes. Force feedback allowed for a gentle and stable contact between AFM tip and cell membrane enabling serial patch clamping and injection without apparent cell damage.
自 20 世纪 70 年代发明以来，膜片钳技术一直是电生理学研究和药物筛选的金标准，因为它是唯一能够准确研究电压门控离子通道的工具，而电压门控离子通道负责动作电位。由于其在药物筛选中的关键作用，人们正在努力创新，以实现更自动化的系统。虽然一些新方法正在制药公司中得到采用，但由于其多功能性，传统的膜片钳在基础研究中仍然无与伦比。在这里，我们将膜片钳技术和原子力显微镜（AFM）技术相结合，从而为膜片钳配备了灵敏的 AFM 力控制。这是通过基于微通道原子力显微镜悬臂的力控纳米移液器 FluidFM 实现的。首先，用钠（NaV1.5）通道证明了该系统与膜片钳电子设备的兼容性及其在全细胞构型中记录电压门控离子通道活性的能力。其次，我们展示了在分离的心肌细胞收缩过程中同时记录膜电流和力发展的可行性。力反馈允许 AFM 尖端和细胞膜之间进行轻柔且稳定的接触，从而实现连续的膜片钳和注入，而不会明显损伤细胞。
