Zhang Hongrui, Wallace Gordon G, Higgins Michael J
ARC Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, AIIM Facility, Innovation Campus, University of Wollongong, Wollongong, NSW 2522, Australia.
Biointerphases. 2019 Mar 29;14(2):021003. doi: 10.1116/1.5082204.
The force required to detach a single fibroblast cell in contact with the conducting polymer, polypyrrole doped with dodecylbenzene, was quantified using the Atomic Force Microscope-based technique, Single Cell Force Spectroscopy. The de-adhesion force for a single cell was 0.64 ± 0.03 nN and predominately due to unbinding of α5β1 integrin complexes with surface adsorbed fibronectin, as confirmed by blocking experiments using antibodies. Monophasic pulsed stimulation (50 μs pulse duration) superimposed on either an applied oxidation (+500) or reduction (-500 mV) constant voltage caused a significant decrease in the de-adhesion force by 30%-45% to values ranging from 0.34 to 0.43 nN (±0.02 nN). The electrical stimulation caused a reduction in the molecular-level jump and plateau interactions, while an opposing increase in nonspecific interactions was observed during the cell de-adhesion process. Due to the monophasic pulsed stimulation, there is an apparent change or weakening of the cell membrane properties, which is suggested to play a role in reducing the cell de-adhesion. Based on this study, pulsed stimulation with optimized threshold parameters represents a possible approach to tune cell interactions and adhesion on conducting polymers.
使用基于原子力显微镜的单细胞力谱技术，对与导电聚合物（掺杂十二烷基苯的聚吡咯）接触的单个成纤维细胞进行分离所需的力进行了量化。单个细胞的脱粘力为0.64±0.03 nN，主要是由于α5β1整合素复合物与表面吸附的纤连蛋白解离，这通过使用抗体的阻断实验得到证实。叠加在施加的氧化（+500）或还原（-500 mV）恒定电压上的单相脉冲刺激（脉冲持续时间50 μs）导致脱粘力显著降低30%-45%，降至0.34至0.43 nN（±0.02 nN）的范围。电刺激导致分子水平的跳跃和平台相互作用减少，而在细胞脱粘过程中观察到非特异性相互作用相反增加。由于单相脉冲刺激，细胞膜特性出现明显变化或减弱，这被认为在降低细胞脱粘中起作用。基于这项研究，具有优化阈值参数的脉冲刺激代表了一种调节细胞与导电聚合物相互作用和粘附的可能方法。
