PLA electrospun nanofibers modified with polypyrrole-grafted gelatin as bioactive electroconductive scaffold

Abstract

Neural tissue engineering is a considerable strategy to generate new viable nerve tissue with the help of a scaffold with appropriate chemical, mechanical, and electrical properties. Surface modification of the electrospun nanofibers can be a suitable approach to increase the electroconductivity and cell attachment features of a scaffold. In this study, a neural tissue engineering scaffold containing polylactic acid (PLA) nanofibers, gelatin, and polypyrrole (PPy) was fabricated to combine electrospun nanofibers' topography benefits with the versatile advantages of gelatin and PPy. To this end, a conductive copolymer was chemically synthesized by grafting various weight ratios of pyrrole on gelatin chains, and then it was grafted on PLA nanofibers’ surface to improve its conductivity and bio interactions. The polypyrrole-grafted gelatin (GP) samples were characterized by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, ultraviolet–visible (UV–vis) spectroscopy, and two-point probe conductivity test. The chemical structure, elemental composition, surface hydrophilicity, surface conductivity, and morphology of the modified scaffolds were evaluated by ATR-FTIR, energy-dispersive X-ray (EDX) spectroscopy, contact angle, two-point probe conductivity, and scanning electron microscopy (SEM) analyses, respectively. Likewise, In vitro studies including [(3-(4, 5- dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide)] (MTT) and cell adhesion investigations were performed using pheochromocytoma (PC12) cells. The results revealed that scaffolds containing 15 and 20% polypyrrole could provide acceptable conditions for the adhesion and growth of nerve cells and can be introduced as a promising scaffold in nerve tissue engineering applications.