Electrically conductive lignin reinforced polyacrylic acid/ hyaluronic acid scaffolds with PEDOT:HA nanoparticles

Hydrogel materials are continually developing in biomedical engineering and recently a lot of effort has gone into their engineered performance in physiological applications. Porosity is an important characteristic for tissue engineering scaffolds to allow enhanced biocompatibility and the pore size needed is dependent on the application and type of tissue for which the hydrogel is being used to regenerate. Regarding biomedical applications, the use of conducting polymers is gaining in popularity due to their promising biocompatibility and potential to stimulate cell growth and proliferation through electrical stimulation. Building on previous hydrogel development by the authors, this study focuses on developing a biocompatible hydrogel scaffold with adjustable porosity and swelling capabilities, robust mechanical properties, electrical conductivity, and high thermal stability. The objective of this work is to examine the effect of freezing temperature, cross-linker and porosity on the final characteristics of the scaffold and to then determine possible applications. The porosity, swelling degree, compression strength, biocompatibility, electrical conductivity, and thermal characteristics of the final material were analyzed and were found to be affected by the varied synthesis methods used. Overall, the synthesized scaffolds exhibit good biocompatibility with increased fluorescence over 3days and over 70% cell viability, thermal stability up to 200°C and a range of swelling of 1725% to 8472%. They also portray robust mechanical properties with a Young's Moduli range of 11kPa to 4.54MPa and a porosity range of 0.78–71.98μm depending on the synthesis methods used. Through variations in synthesis methods, highly porous, absorbent, and stable scaffolds have been synthesized. Notably, this single recipe is highly tailorable for use in a range of biomedical applications from tissue engineering to drug delivery and wound repair.