Conducting Cytocompatible Scaffolds: Composite of Sodium Hyaluronate and Colloidal Particles of Conducting Polymers

Novel bio-inspired conductive scaffolds composed of sodium hyaluronate containing water soluble polyaniline or polypyrrole colloidal particles (concentrations 0.108, 0.054 and 0.036 % w/w) were manufactured. For this purpose, either crosslinking with N-(3-dimethylaminopropyl-N-ethylcarbodiimide hydrochloride and N-hydroxysuccinimid or a freeze-thawing process in the presence of poly(vinylalcohol) were used. The scaffolds comprised interconnected pores with prevailing porosity values of ~30 % and pore sizes enabling the accommodation of cells. Good swelling capacity (92 – 97 %) without any sign of disintegration was typical for all samples. The elasticity modulus depended on the composition of the scaffolds, with the highest value of ~50 000 Pa obtained for the sample containing the highest content of polypyrrole particles. The scaffolds did not possess cytotoxicity and allowed cell adhesion and growth on the surface. Using the in vivo-mimicking conditions in a bioreactor, cells were also able to grow into the structure of the scaffolds. The technique of scaffold preparation used here thus overcomes the limitations of conducting polymers (e.g. poor solubility in an aqueous environment, and limited miscibility with other hydrophilic polymer matrices) and moreover leads to the preparation of cytocompatible scaffolds with potentially cell-instructive properties, which may be of advantage in the healing of damaged electro-sensitive tissues.