The endorsement of functional features such as biocompatibility, mechanical integrity, or electrical conductivity to tissue engineering (TE) scaffolds is essential to stimulate cell adhesion and proliferation. In this study, electrospun nanofibers based on polycaprolactone (PCL) and gelatin (Ge) (ratios 60/40, 50/50, and 40/60), and polyaniline (PAni) particles (0.25, 0.50, and 1.00%wt) were prepared. The time of dissolution in an acid solvent mixture before electrospinning allowed for obtaining nanofibers with controlled features. Changes in the molar mass (Mn from 90·103 to 15·103 g·mol−1), in the crystalline microstructure (Xc from 60 to 25%) and the surface morphology (diameter from 250 to 50 nm) due to the controlled hydrolytic action on PCL were found. In vitro degradability and biocompatibility were favoured as the dissolution time and gelatin percentage increased. The presence of PAni was revealed as non-cytotoxic and promoted a controlled increase of the electrical conductivity, that contributed to in vitro cardiomyocyte proliferation. Cellular centres in the vicinities of PAni microparticles could be identified in the scaffold with the 40/60 PCL/Ge scaffold with PAni (1.00%wt), keeping the macrophages profile unaltered, which may determine the satisfactory resolution of cardiac injury and point out these scaffolds as appropriate candidates for cardiac TE.