Visible Light-Based 4D-Bioprinted Tissue Scaffold

Emerging four-dimensional (4D) printing strategies offer improved alternatives to conventional three-dimensional (3D)bioprinted structures for better compliance and simplicity of application for tissue engineering. Little is reported on simple 3Dbioprinted structures prepared by digital light processing (DLP) that can change shape-to-complex constructs (4D bioprinting) in response to cell-friendly stimuli, such as hydration. In the current research work, a bioink consisting of a blend of gelatin methacryloyl (GelMA) and poly(ethylene glycol) dimethacrylate (PEGDM) with a photoinitiator and a photoabsorber was developed and printed by DLP-based 3D bioprinting operated with visible light (405 nm). The 3D-bioprinted constructs combined with differential cross-linking due to photoabsorber-induced light attenuation were leveraged to realize structural anisotropy, which led to rapid shape deformation (as low as approximate to 30 min) upon hydration. The sheet thickness influenced the degree of curvature, whereas the incorporation of angled strands provided control of the deformation of the 3D-printed structure. The 4Dbioprinted gels supported the viability and proliferation of cells. Overall, this study introduces a cytocompatible bioink formulation for 4D bioprinting to yield shape-morphing, cell-laden hydrogels for tissue engineering.

Automated summary

Emerging 4D printing strategies offer improved alternatives to conventional 3D bioprinted structures for tissue engineering. This research developed a bioink consisting of GelMA and PEGDM with a photoinitiator and a photoabsorber, which can change shape upon hydration. The 4D bioprinted gels supported cell viability and proliferation, providing a cytocompatible bioink formulation for tissue engineering.