Bioprinting of Injectable Centimeter-scale Architectures with a Visible-light Crosslinking Bioink

This study propose a novel visible-light crosslinking hydrogel bioink (termed GP) to fabricate injectable centimeter-scale architectures. Composed of GelMA with large molecular weight PEGDA, GP can form a reinforced dual-crosslinking network, presenting excellent superelasticity and stability, supporting injection pass nozzles with 1.5mm inner diameter after bioprinted as 15mm×15mm scale architectures. Moreover, when printing with living cells, even for sensitive cell lines like genome-edited cells, the transcriptome of cells after printing shows no difference, suggesting the high cell printing suitability of GP and the visible-light extrusion printing technique. The printed architectures can support long-term culture for at least 14 days, and GP provides cells with a biocompatible microenvironment, supporting cell survival, proliferation, and function maintenance. Overall design: For plate cultured samples, HepaRG and gene-edited HepaRG cells (M14A) were cultured in culture flasks. To extract RNA, cells were digested from culture flasks, centrifuged to separate liquid supernatant, and then collected in TRIzol. For after printing samples, M14A cells were digested from culture flasks and gently mixed with GP bioink. 4 hours after printing, the GP printed arhitectures were quick-frozen with liquid nitrogen and ground with mortar and pestle to fracture materials and cell structures. RNA was then extracted using TRIzol.