Free-form co-axial bioprinting of a gelatin methacryloyl bio-ink by direct in situ photo-crosslinking during extrusion

Abstract 3D bioprinting is an emerging technology for arranging cells and biomaterials in 3D, with the goal to develop functional substitutes for damaged tissue. Photo-crosslinkable hydrogels are promising materials for formulating printable bio-inks. However, owing to conflicting constraints around printability and cell survival, achieving good shape fidelity is a challenge. The typical approach to ‘post-crosslink’ a 3D bioprinted structure necessitates highly viscous bio-inks. Meanwhile ‘pre-crosslinking’ can result in the extrusion of overly gelated bio-inks, which increases shear-stresses experienced by encapsulated cells. Neither of these strategies are amenable to creating free-standing structures, or structures with overhangs, without using secondary support materials. Here, for the first time, an on board light exposure strategy is demonstrated which enables rapid (

[1]  James J. Yoo,et al.  A 3D bioprinting system to produce human-scale tissue constructs with structural integrity , 2016, Nature Biotechnology.

[2]  Peter Pivonka,et al.  In situ handheld three‐dimensional bioprinting for cartilage regeneration , 2018, Journal of tissue engineering and regenerative medicine.

[3]  Kristi S Anseth,et al.  Photoinitiated polymerization of PEG-diacrylate with lithium phenyl-2,4,6-trimethylbenzoylphosphinate: polymerization rate and cytocompatibility. , 2009, Biomaterials.

[4]  F. Melchels,et al.  Proposal to assess printability of bioinks for extrusion-based bioprinting and evaluation of rheological properties governing bioprintability , 2017, Biofabrication.

[5]  Gordon G Wallace,et al.  Tailoring the mechanical properties of gelatin methacryloyl hydrogels through manipulation of the photocrosslinking conditions. , 2018, Soft matter.

[6]  Y. S. Zhang,et al.  Effective bioprinting resolution in tissue model fabrication. , 2019, Lab on a chip.

[7]  Feng Xu,et al.  BioPen: direct writing of functional materials at the point of care , 2014, Scientific Reports.

[8]  G. Wallace,et al.  Evaluation of sterilisation methods for bio-ink components: gelatin, gelatin methacryloyl, hyaluronic acid and hyaluronic acid methacryloyl , 2019, Biofabrication.

[9]  Peter Pivonka,et al.  Handheld Co-Axial Bioprinting: Application to in situ surgical cartilage repair , 2017, Scientific Reports.

[10]  P. Choong,et al.  Human articular cartilage repair: Sources and detection of cytotoxicity and genotoxicity in photo‐crosslinkable hydrogel bioscaffolds , 2019, Stem Cells Translational Medicine.

[11]  Robert Langer,et al.  Controlled degradation and mechanical behavior of photopolymerized hyaluronic acid networks. , 2005, Biomacromolecules.

[12]  Ali Khademhosseini,et al.  Functionalization, preparation and use of cell-laden gelatin methacryloyl–based hydrogels as modular tissue culture platforms , 2016, Nature Protocols.

[13]  Yifan Li,et al.  Characterizing Bioinks for Extrusion Bioprinting: Printability and Rheology. , 2020, Methods in molecular biology.

[14]  Savas Tasoglu,et al.  Photocrosslinking-based bioprinting: Examining crosslinking schemes , 2017 .

[15]  P. R. van Weeren,et al.  Gelatin-methacrylamide hydrogels as potential biomaterials for fabrication of tissue-engineered cartilage constructs. , 2013, Macromolecular bioscience.

[16]  G. Wallace,et al.  Bioprinting Stem Cells in Hydrogel for In Situ Surgical Application: A Case for Articular Cartilage. , 2020, Methods in molecular biology.

[17]  Gordon G Wallace,et al.  Development of the Biopen: a handheld device for surgical printing of adipose stem cells at a chondral wound site , 2016, Biofabrication.

[18]  Ibrahim T. Ozbolat,et al.  The bioink: A comprehensive review on bioprintable materials. , 2017, Biotechnology advances.

[19]  Wei Sun,et al.  Effect of bioink properties on printability and cell viability for 3D bioplotting of embryonic stem cells , 2016, Biofabrication.

[20]  K H Kang,et al.  Rapid 3D printing of anatomically accurate and mechanically heterogeneous aortic valve hydrogel scaffolds , 2012, Biofabrication.

[21]  G. Prestwich,et al.  Photocrosslinkable hyaluronan-gelatin hydrogels for two-step bioprinting. , 2010, Tissue engineering. Part A.

[22]  T. Alan Hatton,et al.  Modeling of Oxygen-Inhibited Free Radical Photopolymerization in a PDMS Microfluidic Device , 2008 .

[23]  Robert Langer,et al.  Tissue engineering: the design and fabrication of living replacement devices for surgical reconstruction and transplantation , 1999, The Lancet.

[24]  Elise M. Stewart,et al.  3D printing of layered brain-like structures using peptide modified gellan gum substrates. , 2015, Biomaterials.

[25]  G. Wallace,et al.  Biofabrication of human articular cartilage: a path towards the development of a clinical treatment , 2018, Biofabrication.

[26]  Mark W. Tibbitt,et al.  Hydrogels as extracellular matrix mimics for 3D cell culture. , 2009, Biotechnology and bioengineering.

[27]  Chee Kai Chua,et al.  Layer-by-layer ultraviolet assisted extrusion-based (UAE) bioprinting of hydrogel constructs with high aspect ratio for soft tissue engineering applications , 2019, PloS one.

[28]  Liliang Ouyang,et al.  A Generalizable Strategy for the 3D Bioprinting of Hydrogels from Nonviscous Photo‐crosslinkable Inks , 2017, Advanced materials.