Piezoelectric nanofibrous scaffolds as in vivo energy harvesters for modifying fibroblast alignment and proliferation in wound healing

Since the last decade, piezoelectric polymer nanofibers have been of great interest in the stimulation of cell growth and proliferation for tissue engineering and wound healing applications. To date, there is no clear understanding of how the piezoelectric properties of piezoelectric materials can be affected by electrospinning parameters and how the piezoelectricity from the electrospun polymer nanofibers produced under optimized electrospinning conditions in vivo would affect cell growth, proliferation and elongation. In this paper, it is shown for the first time how electrospinning parameters, such as solution concentration and collecting distance (from the needle to the rotating mandrel), can affect the piezoelectricity of the poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) nanofibers. Here, the optimized electrospinning conditions for P(VDF-TrFE) nanofibers were achieved and these nanofiber scaffolds (NFSs) were used for implanted energy harvester in SD rats, cell proliferation and cell alignment growth applications. During the process of slightly pulling implanted site of SD rats, the implanted PVDF-TrFE NFSs generated a maximum voltage and current of 6 mV and ~6 nA, respectively. With great cytocompatibility and relatively large piezoelectric effect, fibroblast cells grew and aligned perfectly along the electrospinning direction of P(VDF-TrFE) nanofiber direction and cell proliferation rate was enhanced by 1.6 fold. Thus, electrospun P(VDF-TrFE) NFSs show great promise in tissue engineering and wound healing applications.