Fabrication of a biocompatible electroconductive scaffold based on ascorbic acid-doped polyaniline for bone tissue engineering

One of the main challenges of using polyaniline (PANI) in tissue engineering, is the cytotoxicity of PANI dopants, which compromises their biocompatibility. Herein, we aimed to substitute a biocompatible dopant instead of other cytotoxic dopants such as, camphor sulfonic acid (CSA). For this purpose, poly-L-lactic acid (PLLA) was used as a carrier polymer, PANI as a conductive agent, and AA as a biological factor and PANI dopant. Conductive scaffolds were fabricated via electrospinning. Finally, the morphology of the scaffolds was evaluated using a scanning electron microscope (SEM). By adding PANI, CSA and AA dopants to PLLA, we observed a decrease in the diameter of nanofibers from 841 ± 181 nm to 468 ± 62 nm and from 841 ± 181 nm to 546 ± 77 nm, respectively. The conductivity of the scaffolds was measured by the two-point probe, which was 9.7 × 10–5 in the PANI-CSA scaffold and 4 × 10–5 in the PANI-AA scaffold. Considering that the acidity of CSA is higher than the acidity of AA, its polymer solution has more conductivity and leads to a decrease in the diameter of nanofibers. Therefore, we proposed that PANI-AA-based nanofibers can be used as a bioactive conductive scaffold for bone tissue engineering. Since AA does not have the cytotoxicity of CSA and in addition to playing a biological role that causes bone differentiation, it also has the role of a dopant for PANI.