3D bioprinting of an electroactive and self-healing polysaccharide hydrogels

Polysaccharide hydrogels including alginate, agarose, hyaluronic acid, and chitosan have been widely used as scaffolds in 3D bio-printing field. Konjac glucomannan (KGM) exhibits excellent properties of water solubility, biocompatibility, and biodegradability. Herein composite hydrogels were prepared via Schiff-base reaction between the aldehyde group of oxidized konjac glucomannan (OKGM) and the amino group of branched polyethyleneimine (PEI). The OKGM/PEI composite hydrogel displayed self-healing ability and pH sensitivity and showed shear thinning capability, which is suitable for 3D bio-printing technology. Furthermore, the OKGM/PEI electroactive composite hydrogel was obtained by adding carbon nanotubes (CNTs). Then the rheological behavior and morphology of OKGM/PEI electroactive hydrogels were thoroughly characterized. The conductivities of OKGM/PEI electroactive composite hydrogels increased with increasing the content of CNTs. The rheological behavior and 3D bio-printability of OKGM/PEI electroactive hydrogels were also tested. It was found that CNTs can also improve the bio-printability of OKGM/PEI electroactive hydrogels. Thus, the OKGM/PEI electroactive hydrogels could be employed as scaffolds for muscle and cardiac nerve tissue regeneration.