Bioelectricity plays a vital role in regulating cellular behavior. During the process of tissue repair and regeneration, surface electrical signals provided by biomaterials are found to be helpful. The characteristics of these electrical signals typically vary depending on the specific tissue repair requirements. In this study, zinc oxide nanorod (ZNR) arrays were loaded onto a poly(vinylidene fluoride-trifluoroethylene) (PVTF) substrate via the hydrothermal method. The nanorods were subsequently tilted by uniaxial stretching to form a ZNR/PVTF composite film with in-plane, horizontally aligned ZNRs along the stretching direction on the surface. The distribution of ZNRs created a heterogeneous potential across the PVTF substrate. Under ultraviolet (UV) irradiation, the surface potential of the ZNRs increased by approximately 76 mV due to a photoelectric response, enabling the formation of an adjustable millivolt-level surface potential. After corona polarization, the dipoles within the PVTF were aligned to achieve piezoelectric properties. The existence of oriented surface ZNRs enhanced the piezoelectric response of the ZNR/PVTF film, allowing for volt-level dynamic electrical signals through a force-voltage coupling mechanism. The output voltage increased from 1.32 V (PVTF) to 2.42 V (ZNR/PVTF) under the same 30° bending condition. Moreover, the ZNR/PVTF film exhibited excellent short-term biocompatibility toward bone marrow stem cells (BMSCs). Overall, this work presents an effective strategy for generating multiscale electrical signals through external field applications, demonstrating strong potential for tissue repair and regeneration.
Fan et al. (Mon,) studied this question.