Carbon nanofillers incorporated electrically conducting poly ε-caprolactone nanocomposite films and their biocompatibility studies using MG-63 cell line

Poly ε-caprolactone (PCL)-based nanocomposite films were prepared by solvent casting method with different electrically conducting carbon nanofillers like carbon nanofiber (CNF), nanographite and liquid exfoliated graphite. These nanocomposite films show remarkable increase in both surface and bulk electrical conductivity. Continuous network of nanofillers in polymer matrix was observed under high-resolution transmission electron microscopy (HRTEM). The spreading resistance images in AFM showed the presence of nanofillers on the nanocomposite films. These films reveal strong directional effect in electrical conductivity towards longitudinal direction than transverse. PCL film dispersed with 10 % (w/w) CNF showed an electrical conductivity of 19 S/m at longitudinal direction as compared to 1 S/m at transverse direction. This can be best explained with the arrangement of nanofillers along longitudinal direction during solution casting method which is evident from HRTEM images. The electrical conductivity of the nanocomposite films increased in the presence of phosphate buffer saline and simulated body fluid with time. MTT and nuclear staining experiments with osteoblast MG63 cells clearly demonstrated good biocompatibility of these materials. Among all the nanofillers, CNF looks most promising for biomedical applications of PCL-based conducting nanocomposites, as it shows high electrical conductivity and good cell proliferation.