Synthesis and characterization of electrospun PCL-PVA-PPy-rGO fibers as a novel scaffold for bone tissue engineering

Electroconductive fibers based on Polycaprolactone (PCL) and Polypyrrole (PPy) possess considerable potential for bone tissue engineering due to their biocompatibility and biodegradability. However, low electrical conductivity in composites fabricated via direct blending of conductive particles into polymer solutions, as well as limited hydrophilicity, remain major challenges of PCL-PPy scaffolds. In this study, to overcome these limitations and simultaneously improve electrical, mechanical, surface, and biological properties, reduced graphene oxide (rGO, 0–1 wt%) and Polyvinyl alcohol (PVA) were employed to fabricate a PCL-PVA-PPy-rGO composite via electrospinning. In PCL-PVA fibers, the PVA improved morphology, tensile strength, and hydrophilicity of PCL fibers. The incorporation of PPy decreased the tensile strength of PCL-PVA fibers; however, rGO partially compensated for this reduction. The addition of PPy resulted in a remarkable increase in electrical conductivity, while the subsequent incorporation of rGO provided a smaller incremental enhancement. Furthermore, PPy, and rGO reduced the weight loss of PCL–PVA fibers in phosphate-buffered saline solution. From a biological perspective, rGO enhanced metabolic activity, cell attachment and spreading, and calcium deposition. Overall, the combined incorporation of PVA and rGO improved the electrical, mechanical, surface, and biological properties of PCL-PPy-based fibers, while the PPPrGO-0.5 formulation exhibited the most favorable overall balance of the evaluated properties, indicating its potential for bone tissue engineering applications.