Biomineralization and biocompatibility studies of bone conductive scaffolds containing poly(3,4-ethylenedioxythiophene): poly(4-styrene sulfonate) (PEDOT:PSS)

Considering the well-known phenomenon of enhancing bone healing by applying electromagnetic stimulation, manufacturing conductive bone scaffolds is on demand to facilitate the delivery of electromagnetic stimulation to the injured region, which in turn significantly expedites the healing procedure in tissue engineering methods. For this purpose, hybrid conductive scaffolds composed of poly(3,4-ethylenedioxythiophene), poly(4-styrene sulfonate) (PEDOT: PSS), gelatin (Gel), and bioactive glass (BaG) were produced employing freeze drying technique. Concentration of PEDOT: PSS were optimized to design the most appropriate conductive scaffold in terms of biocompatibility and cell proliferation. More specifically, scaffolds with four different compositions of 0, 0.1, 0.3 and 0.6 % (w/w) PEDOT: PSS in the mixture of 10 % (w/v) Gel and 30 % (w/v) BaG were synthesized. Immersing the scaffolds in simulated body fluid (SBF), we evaluated the bioactivity of samples, and the biomineralization were studied in details using scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction analysis and Fourier transform infrared spectroscopy. By performing cytocompatibility analyses for 21 days using adult human mesenchymal stem cells, we concluded that the scaffolds with 0.3 % (w/w) PEDOT: PSS and conductivity of 170 lS/m has the optimized composition and further increasing the PEDOT: PSS content has inverse effect on cell proliferation. Based on our finding, addition of this optimized amount of PEDOT: PSS to our composition can increase the cell viability more than 4 times compared to a nonconductive composition.