Wang Aochen, Hu Ming, Zhou Liwei, Qiang Xiaoyong
School of Microelectronics, Tianjin University, Tianjin 300072, China.
Nanomaterials (Basel). 2019 Mar 3;9(3):349. doi: 10.3390/nano9030349.
Electric potential plays an indispensable role in tissue engineering and wound healing. Piezoelectric nanogenerators based on direct piezoelectric effects can be self-powered energy sources for electrical stimulation and have attracted extensive attention. However, the accuracy of piezoelectric stimuli on piezoelectric polymers membranes in vitro during the dynamic condition is rarely studied. Here, a self-powered tunable electrical stimulation system for assisting the proliferation of preosteoblasts was achieved by well-aligned P(VDF-TrFE) piezoelectric nanofiber membrane (NFM) both as a nanogenerator (NG) and as a scaffold. The effects of electrospinning and different post-treatments (annealing and poling) on the surface wettability, piezoelectric β phase, ferroelectric properties, and sensing performance of NFMs were evaluated here. The polarized P(VDF-TrFE) NFM offered an enhanced piezoelectric value (d of 22.88 pC/N) versus pristine P(VDF-TrFE) NFM (d of 0.03 pC/N) and exhibited good sensing performance. The maximum voltage and current output of the P(VDF-TrFE) piezoelectric nanofiber NGs reached -1.7 V and 41.5 nA, respectively. An accurate electrical response was obtained in real time under dynamic mechanical stimulation by immobilizing the NGs on the flexible bottom of the culture plate, thereby restoring the real scene of providing electrical stimulation to the cells in vitro. In addition, we simulated the interaction between the piezoelectric nanofiber NG and cells through an equivalent circuit model. To verify the feasibility of P(VDF-TrFE) nanofiber NGs as an exact electrical stimulation, the effects of different outputs of P(VDF-TrFE) nanofiber NGs on cell proliferation in vitro were compared. The study realized a significant enhancement of preosteoblasts proliferation. This work demonstrated the customizability of P(VDF-TrFE) piezoelectric nanofiber NG for self-powered electrical stimulation system application and suggested its significant potential application for tissue repair and regeneration.
电势在组织工程和伤口愈合中发挥着不可或缺的作用。基于直接压电效应的压电纳米发电机可作为用于电刺激的自供电能源，已引起广泛关注。然而，动态条件下压电聚合物膜体外压电刺激的准确性鲜有研究。在此，通过将排列良好的聚（偏二氟乙烯-三氟乙烯）（P(VDF-TrFE)）压电纳米纤维膜（NFM）既用作纳米发电机（NG）又用作支架，实现了一种用于辅助前成骨细胞增殖的自供电可调电刺激系统。本文评估了静电纺丝和不同后处理（退火和极化）对NFM表面润湿性、压电β相、铁电性能和传感性能的影响。极化的P(VDF-TrFE) NFM相对于原始P(VDF-TrFE) NFM（d为0.03 pC/N）具有更高的压电值（d为22.88 pC/N），并表现出良好的传感性能。P(VDF-TrFE)压电纳米纤维NG的最大电压和电流输出分别达到-1.7 V和41.5 nA。通过将NG固定在培养板的柔性底部，在动态机械刺激下实时获得了精确的电响应，从而恢复了体外向细胞提供电刺激的真实场景。此外，我们通过等效电路模型模拟了压电纳米纤维NG与细胞之间的相互作用。为验证P(VDF-TrFE)纳米纤维NG作为精确电刺激的可行性，比较了P(VDF-TrFE)纳米纤维NG不同输出对体外细胞增殖的影响。该研究实现了前成骨细胞增殖的显著增强。这项工作证明了P(VDF-TrFE)压电纳米纤维NG在自供电电刺激系统应用中的可定制性，并表明其在组织修复和再生方面具有巨大的潜在应用价值。
