Synthesis and characterization of biphasic layered structure composite with simultaneous electroconductive and piezoelectric behavior as a scaffold for bone tissue engineering

Abstract In recent years, materials with piezoelectric and electroconductive behavior have been thought interesting and important to be used for bone scaffolds due to their potential in mimicking the bone tissues. In the present work, attempts have been made to prepare three‐dimensional laminated scaffolds by means of embedding the piezoelectric polyvinylidene fluoride (PVDF)/polylactic acid (PLA) electrospun nanofibrous mats into the electroconductive porous oxidized alginate (ADA)/gelatin/polypyrrole‐graft‐gelatin (PPy‐g‐gelatin) hydrogel precursor structure to obtain a biphasic layered structure (a fiber‐hydrogel scaffold). The morphology, tensile strength, β‐phase contents, and crystallinity of the fibers are evaluated. The compressive modulus of the electrospun fiber‐hydrogel composites (32.72 MPa) shows to be much higher than the neat hydrogel (0.01 MPa). The prepared composites present high electrical conductivity (1.8 S m −1 ) and piezoelectric coefficient (1.61 fC N −1 ). By incorporating the fibers into the hydrogel structure, the cross‐link density of the composite is increased. The swelling ratio, porosity, and rate of biodegradation of the fabricated composites are also investigated. Moreover, good biocompatibility of human osteosarcoma cells attached to the PVDF/PLA nanofibers‐ADA/gelatin/PPy‐g‐gelatin hydrogel scaffold is evidenced by alkaline phosphatase assay, alizarin red and hematoxylin and eosin staining, and osteogenic gene expression evaluation. The prepared osteon‐mimetic samples with the synergized features of piezoelectricity and electrical conductivity can potentially be used as three‐dimensional scaffolds for bone tissue engineering.