A dual-crosslinking electroactive hydrogel based on gelatin methacrylate and dibenzaldehyde-terminated telechelic polyethylene glycol for 3D bio-printing

Abstract

Abstract Gelatin was widely used as scaffold materials in 3D bio-printing due to its excellent bioactivity and availability and especially that their arginine-glycine-aspartic acid (RGD) sequences could efficiently promote cell adhesion and proliferation. In this study, physical-chemical double crosslinked gelatin methacrylate-based electroactive hydrogel was prepared via Schiff-base reaction between the free amino groups of gelatin methacrylate (GelMA) and the aldehyde groups of dibenzaldehyde-terminated telechelic polyethylene glycol (DF-PEG), and meanwhile multi-walled carbon nanotubes (MWCNTs) were homogeneously distributed into GelMA solution. The optimized GelMA/DF-PEG composite hydrogel, i.e., 30% GelMA and 25% DF-PEG (G30D25-CNTs), exhibited superior bio-printability. When the content of CNTs was above 4%, the conductivity of G30D25-CNTs hydrogel exceeded 10− 2 S/m, which satisfied the needs of cells for micro-current stimulation. Furthermore, the swelling behavior and degradation ability of G30D25-CNTs electroactive hydrogels were thoroughly evaluated. Thus, the G30D25-CNTs hydrogel with 4% MWCNTs could be considered for further application in electrical stimulation of tissue regeneration such as muscle and cardiac nerve tissue repair.