Electrical Properties And Cytocompatibility Study Of Electrospun PVDF Films

PVDF is main piezoelectric polymer, which has direct and reversed piezoelectric effect,with lending electroactive, flexible, and inexpensive properties, it has attracted intensive interests in energy transmission system. Most of researchers were focusing on electrospinning PVDF fibers meshes to transfer mechanical energy into electric energy for sensor devices.However there were few reports about reversed piezoelectric effect applications and researches, especially for transferring electric energy into mechanical energy in tissue engineering, mainly by decreasing impedance of PVDF fiber meshes, to make reversed piezoelectric effect in lower electric frequency.In this project the electrospinning technique has been used to prepare PVDF(polyvinylidene fluoride) and PVDF/PLGA [poly(lactic-co-glycolic acid)] blended polymeric scaffolds for tissue engineering. The main objective is the preparation of electroactuated devices for cell stimulation.Crystal phase changes and morphology of the PVDF fibre mesh surface were characterized by attenuated total reflectance Fourier transform infrared(FTIR/ATR)spectroscopy and scanning electron micrograph(SEM). Several devices were prepared from assemblies of PVDF fibre meshes and conductive ink electrodes, with different geometries.The devices’ electrical impedance was measured as a function of frequency. Finally, the in vitro biocompatibility of the PVDF fibre meshes was tested.The results revealed that electrospinning parameters had significant effects on crystal phase content and structure. As it was expected, the electrical impedance of PVDF decreased with the increase of β crystal phase content, as required for the electrostrictive behaviour of the PVDF fibres. The results also illustrated that the impedance of PVDF fibre mesh assemblies changed with varying shape, thickness, the geometric alignment of the fibres and the distance between conductive ink electrodes. In vitro cytocompatibility tests of PVDF scaffolds shown that the NIH3T3 cells cultured on scaffolds were alive which meant PVDF biocompatibility was acceptable for biomedical applications.The use of PVDF polymer fibres for electromechanical stimulation of living cells will be tried and its effects on the biological activity of specific tissue cells(bone, muscle,nervous).will be studied. The potential use of electroactive polymers, conductor or semiconductor polymers for sensor applications will be looked upon, taking as long time objective the design of micro-nano-bio systems devices and application.