In the past decade, nanostructured polypyrrole (PPy) has been widely studied because of its many specific properties, which have obvious advantages over bulk-structured PPy. This review outlines the main structures, preparation methods, physicochemical properties, potential applications, and future prospects of PPy nanomaterials. The preparation approaches include the soft micellar template method, hard physical template method and templateless method. Due to their excellent electrical conductivity, biocompatibility, environmental stability and reversible redox properties, PPy nanomaterials have potential applications in the fields of energy storage, biomedicine, sensors, adsorption and impurity removal, electromagnetic shielding, and corrosion resistant. Finally, the current difficulties and future opportunities in this research area are discussed.

The fabrication of scaffolds with suitable chemical, physical, and electrical properties is critical for nerve cell adhesion and proliferation. Recently, electrical stimulation on conductive polymers has been applied to construct functional nerve cell scaffolds. Herein, we prepared natural polymer (cellulose)/conductive polymer nanofibrous mats, i.e., electrospun cellulose (EC)/poly N-vinylpyrrole (PNVPY) and EC/poly(3-hexylthiophene) (P3HT) through an efficient in situ polymerization method. The surface immobilization was characterized by optical microscopy (OM), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, hydrophilicity, porosity, and cyclic voltammetry. The OM and SEM images showed that PNVPY formed polymer coatings and aggregated nanoparticles on the EC nanofibers, while P3HT only produced polymer coatings. Compared with pure EC mats, both the composite mats had increased thickness, higher porosity, and higher conductivity. Also, an increase in hydrophilicity was found for EC/P3HT. In vivo cytocompatibility of the undifferentiated PC12 cells showed that the EC/PNVPY and EC/P3HT scaffolds exhibited favorable cell activity, adhesion, and proliferation. Furthermore, the results of electrical stimulation experiments indicated that the EC/P3HT mats could effectively promote the proliferation of the PC12 cells more than the EC and EC/PNVPY mats. The findings suggest a positive outcome regarding the conductive polymer-modified EC/PNVPY and EC/P3HT nanofibrous mats in neural tissue engineering.