Abstract
The development of biocompatible and precisely printable bioink addresses the growing demand for three-dimensional (3D) bioprinting applications in the field of tissue engineering. We developed a methacrylated photocurable silk fibroin (SF) bioink for digital light processing 3D bioprinting to generate structures with high mechanical stability and biocompatibility for tissue engineering applications. Procedure 1 describes the synthesis of photocurable methacrylated SF bioink, which takes 2 weeks to complete. Digital light processing is used to fabricate 3D hydrogels using the bioink (1.5 h), which are characterized in terms of methacrylation, printability, mechanical and rheological properties, and biocompatibility. The physicochemical properties of the bioink can be modulated by varying photopolymerization conditions such as the degree of methacrylation, light intensity, and concentration of the photoinitiator and bioink. The versatile bioink can be used broadly in a range of applications, including nerve tissue engineering through co-polymerization of the bioink with graphene oxide, and for wound healing as a sealant. Procedure 2 outlines how to apply 3D-printed SF hydrogels embedded with chondrocytes and turbinate-derived mesenchymal stem cells in one specific in vivo application, trachea tissue engineering, which takes 2–9 weeks.
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Data availability
The main data discussed in this protocol are available in the supporting primary research papers: ref. 17 (https://doi.org/10.1038/s41467-018-03759-y), ref. 36(https://doi.org/10.1016/j.biomaterials.2019.119679), ref. 70 (https://doi.org/10.1016/j.biomaterials.2020.120281), ref. 71 (https://doi.org/10.1021/acs.nanolett.0c02986), and ref. 68 (https://doi.org/10.1038/s41427-020-0227-6).
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Acknowledgements
This work was supported by the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI) funded by the Ministry of Health & Welfare, Republic of Korea (HI20C0408), the Industrial Technology Alchemist Project (20012327) funded by the Ministry of Trade, Industry & Energy (MOTIE, Korea), and Hallym University Research Fund.
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All authors contributed to experimental work shown in this protocol. C.H.P. supervised the project and provided funding. S.H.K. conceived and managed the manuscript preparation. S.H.K., H.H., O.A. and M.T.S. drafted and revised the manuscript with input from all authors. Y.J.L., J.S.L., O.J.L., H.L., H.S.P., K.Y.C., J.S.L., H.W.J. and I.S.H. partially wrote the manuscript. All authors read and approved the final manuscript.
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Key references using this protocol
Kim, S. H. et al. Nat. Commun. 9, 1–14 (2018): https://doi.org/10.1038/s41467-018-03759-y
Hong, H. et al. Biomaterials 232, 119679 (2020): https://doi.org/10.1016/j.biomaterials.2019.119679
Kim, S. H. et al. Biomaterials 260, 120281 (2020): https://doi.org/10.1016/j.biomaterials.2020.120281
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Supplementary Fig. 1.
Supplementary Data 1
Square model for cytocompatibility test
Supplementary Data 2
Human trachea CAD model
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Kim, S.H., Hong, H., Ajiteru, O. et al. 3D bioprinted silk fibroin hydrogels for tissue engineering. Nat Protoc 16, 5484–5532 (2021). https://doi.org/10.1038/s41596-021-00622-1
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DOI: https://doi.org/10.1038/s41596-021-00622-1
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