Printable alginate/gelatin hydrogel reinforced with carbon nanofibers as electrically conductive scaffolds for tissue engineering.

Shortages of organs and damaged tissues for transplantation have prompted improvements in biomaterials within the field of tissue engineering (TE). The rise of hybrid hydrogels as electro-conductive biomaterials offers promise in numerous challenging biomedical applications. In this work, hybrid printable biomaterials comprised of alginate and gelatin hydrogel systems filled with carbon nanofibers (CNFs) were developed to create electroconductive and printable 3-D scaffolds. Importantly, the preparation method allows the formation of hydrogels with homogenously dispersed CNFs. These hybrid composite hydrogels were evaluated in terms of mechanical, chemical and cellular response. They display excellent mechanical performance, which is augmented by the CNFs, with Young's moduli and conductivity reaching 534.7 ± 2.7 kPa and 4.1 × 10-4 ± 2 × 10-5 S/cm respectively. CNF incorporation enhances shear-thinning behaviour, allowing ease of 3-D printing. In-vitro studies indicate improved cellular proliferation compared to controls. These conductive hydrogels have the potential to be used in a myriad of TE strategies, particularly for those focused on the incorporation of electroconductive components for applications such as cardiac or neuronal TE strategies.