Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Intravital three-dimensional bioprinting

Nature Biomedical Engineering volume 4, pages 901–915 (2020)Cite this article

Subjects

Abstract

Fabrication of three-dimensional (3D) structures and functional tissues directly in live animals would enable minimally invasive surgical techniques for organ repair or reconstruction. Here, we show that 3D cell-laden photosensitive polymer hydrogels can be bioprinted across and within tissues of live mice, using bio-orthogonal two-photon cycloaddition and crosslinking of the polymers at wavelengths longer than 850 nm. Such intravital 3D bioprinting—which does not create by-products and takes advantage of commonly available multiphoton microscopes for the accurate positioning and orientation of the bioprinted structures into specific anatomical sites—enables the fabrication of complex structures inside tissues of live mice, including the dermis, skeletal muscle and brain. We also show that intravital 3D bioprinting of donor-muscle-derived stem cells under the epimysium of hindlimb muscle in mice leads to the de novo formation of myofibres in the mice. Intravital 3D bioprinting could serve as an in vivo alternative to conventional bioprinting.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Get just this article for as long as you need it

$39.95

Learn more

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Intravital 3D bioprinting setup and in vivo application.
Fig. 2: Development of injectable HCC-conjugated polymers for i3D bioprinting application.
Fig. 3: Characterization of the photosensitive polymers.
Fig. 4: Three-dimensional objects of photosensitive gelatin hydrogels can be used for in vitro cell culture.
Fig. 5: HCC–gelatin hydrogels can be fabricated into pre-existing 3D environments and are suitable for 3D in vitro hSIO culture.
Fig. 6: Intravital 3D bioprinting.
Fig. 7: Cell-laden i3D bioprinting.

Data availability

The main data supporting the results in this study are available within the paper and its Supplementary Information. The raw image data and the analysed data generated in this study are available from the corresponding author upon reasonable request.

References

  1. Kruth, J. P. Material incress manufacturing by rapid prototyping techniques. CIRP Ann. Manuf. Technol. 40, 603–614 (1991).

    Article  Google Scholar 

  2. Gross, B. C., Erkal, J. L., Lockwood, S. Y., Chen, C. & Spence, D. M. Evaluation of 3D printing and its potential impact on biotechnology and the chemical sciences. Anal. Chem. 86, 3240–3253 (2014).

    Article  CAS  PubMed  Google Scholar 

  3. Moroni, L. et al. Biofabrication strategies for 3D in vitro models and regenerative medicine. Nat. Rev. Mater. 3, 21–37 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  4. Murphy, S. V. & Atala, A. 3D bioprinting of tissues and organs. Nat. Biotechnol. 32, 773–785 (2014).

    Article  CAS  PubMed  Google Scholar 

  5. Ong, C. S. et al. 3D bioprinting using stem cells. Pediatr. Res. 83, 223–231 (2018).

    Article  CAS  PubMed  Google Scholar 

  6. Kang, H. W. et al. A 3D bioprinting system to produce human-scale tissue constructs with structural integrity. Nat. Biotechnol. 34, 312–319 (2016).

    Article  CAS  PubMed  Google Scholar 

  7. Hong, N., Yang, G.-H., Lee, J. & Kim, G. 3D bioprinting and its in vivo applications. J. Biomed. Mater. Res. B 106, 444–459 (2018).

    Article  CAS  Google Scholar 

  8. Wang, M. et al. The trend towards in vivo bioprinting. Int. J. Bioprint. 1, 15–26 (2015).

    Google Scholar 

  9. Skardal, A. et al. Bioprinted amniotic fluid-derived stem cells accelerate healing of large skin wounds. Stem Cells Transl. Med. 1, 792–802 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  10. Binder, K. W. et al. In situ bioprinting of the skin for burns. J. Am. Coll. Surg. 211, S76 (2010).

    Article  Google Scholar 

  11. Keriquel, V. et al. In situ printing of mesenchymal stromal cells, by laser-assisted bioprinting, for in vivo bone regeneration applications. Sci. Rep. 7, 1–10 (2017).

    Article  CAS  Google Scholar 

  12. Di Bella, C. et al. In situ handheld three-dimensional bioprinting for cartilage regeneration. J. Tissue Eng. Regen. Med 12, 611–621 (2018).

    Article  CAS  PubMed  Google Scholar 

  13. Wang, X., Rivera-Bolanos, N., Jiang, B. & Ameer, G. A. Advanced functional biomaterials for stem cell delivery in regenerative engineering and medicine. Adv. Funct. Mater. 29, 1–31 (2019).

    CAS  Google Scholar 

  14. Zhang, Z., Wang, B., Hui, D., Qiu, J. & Wang, S. 3D bioprinting of soft materials-based regenerative vascular structures and tissues. Composites B 123, 279–291 (2017).

    Article  CAS  Google Scholar 

  15. Chin, S. Y. et al. Additive manufacturing of hydrogel-based materials for next-generation implantable medical devices. Sci. Robot. 2, eaah6451 (2017).

    Article  Google Scholar 

  16. Murphy, S. V., Skardal, A. & Atala, A. Evaluation of hydrogels for bio-printing applications. J. Biomed. Mater. Res. A 101, 272–284 (2013).

    Article  PubMed  CAS  Google Scholar 

  17. König, K. Multiphoton microscopy in life sciences. J. Microsc. 200, 83–104 (2000).

    Article  PubMed  Google Scholar 

  18. Chang, H., Shi, M., Sun, Y. & Jiang, J. Photo-dimerization characteristics of coumarin pendants within amphiphilic random copolymer micelles. Chin. J. Polym. Sci. 33, 1086–1095 (2015).

    Article  CAS  Google Scholar 

  19. Mahon, M. F., Raithby, P. R. & Sparkes, H. A. Investigation of the factors favouring solid state [2+2] cycloaddition reactions; the [2+2] cycloaddition reaction of coumarin-3-carboxylic acid. CrystEngComm 10, 573–576 (2008).

    Article  CAS  Google Scholar 

  20. Wang, D., Hou, X., Ma, B., Sun, Y. & Wang, J. UV and NIR dual-responsive self-assembly systems based on a novel coumarin derivative surfactant. Soft Matter 13, 6700–6708 (2017).

    Article  CAS  PubMed  Google Scholar 

  21. Belfield, K. D., Bondar, M. V., Liu, Y. & Przhonska, O. V. Photophysical and photochemical properties of 5,7-di- methoxycoumarin under one- and two-photon excitation. J. Phys. Org. Chem. 16, 69–78 (2002).

    Article  CAS  Google Scholar 

  22. Iliopoulos, K., Krupka, O., Gindre, D. & Salle, M. Reversible two-photon optical data storage in coumarin-based copolymers. J. Am. Chem. Soc. 132, 14343–14345 (2010).

    Article  CAS  PubMed  Google Scholar 

  23. Kim, S. H., Sun, Y., Kaplan, J. A., Grinstaff, M. W. & Parquette, J. R. Photo-crosslinking of a self-assembled coumarin-dipeptide hydrogel. N. J. Chem. 39, 3225–3228 (2015).

    Article  CAS  Google Scholar 

  24. Kabb, C. P., O’Bryan, C. S., Deng, C. C., Angelini, T. E. & Sumerlin, B. S. Photoreversible covalent hydrogels for soft-matter additive manufacturing. ACS Appl. Mater. Interfaces 10, 16793–16801 (2018).

    Article  CAS  PubMed  Google Scholar 

  25. Zhu, C. & Bettinger, C. J. Light-induced remodeling of physically crosslinked hydrogels using near-IR wavelengths. J. Mater. Chem. B 2, 1613–1618 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  26. Azagarsamy, M. A., McKinnon, D. D., Alge, D. L. & Anseth, K. S. Coumarin-based photodegradable hydrogel: design, synthesis, gelation, and degradation kinetics. ACS Macro Lett. 3, 515–519 (2014).

    Article  CAS  Google Scholar 

  27. Williams, C. G., Malik, A. N., Kim, T. K., Manson, P. N. & Elisseeff, J. H. Variable cytocompatibility of six cell lines with photoinitiators used for polymerizing hydrogels and cell encapsulation. Biomaterials 26, 1211–1218 (2005).

    Article  CAS  PubMed  Google Scholar 

  28. Torgersen, J. et al. Hydrogels for two-photon polymerization: A toolbox for mimicking the extracellular matrix. Adv. Funct. Mater. 23, 4542–4554 (2013).

    Article  CAS  Google Scholar 

  29. Xing, J.-F., Zheng, M.-L. & Duan, X.-M. Two-photon polymerization microfabrication of hydrogels: an advanced 3D printing technology for tissue engineering and drug delivery. Chem. Soc. Rev. 44, 5031–5039 (2015).

    Article  CAS  PubMed  Google Scholar 

  30. Ingber, D. E. Cellular mechanotransduction: putting all the pieces together again. FASEB J. 20, 811–827 (2006).

    Article  CAS  PubMed  Google Scholar 

  31. Dupont, S. et al. Role of YAP/TAZ in mechanotransduction. Nature 474, 179–184 (2011).

    Article  CAS  PubMed  Google Scholar 

  32. Bian, L. et al. The influence of hyaluronic acid hydrogel crosslinking density and macromolecular diffusivity on human MSC chondrogenesis and hypertrophy. Biomaterials 34, 413–421 (2013).

    Article  CAS  PubMed  Google Scholar 

  33. Brigo, L. et al. 3D high-resolution two-photon crosslinked hydrogel structures for biological studies. Acta Biomater. 55, 373–384 (2017).

    Article  CAS  PubMed  Google Scholar 

  34. Lefort, C. A review of biomedical multiphoton microscopy and its laser sources. J. Phys. D 50, 423001 (2017).

    Article  CAS  Google Scholar 

  35. Ostrovidov, S. et al. Skeletal muscle tissue engineering: methods to form skeletal myotubes and their applications. Tissue Eng. B 20, 403–436 (2014).

    Article  Google Scholar 

  36. Moon, D. G., Christ, G., Stitzel, J. D., Atala, A. & Yoo, J J. Cyclic mechanical preconditioning improves engineered muscle contraction. Tissue Eng. A 14, 473–482 (2008).

    Article  CAS  Google Scholar 

  37. Gjorevski, N. et al. Designer matrices for intestinal stem cell and organoid culture. Nature 539, 560–564 (2016).

    Article  CAS  PubMed  Google Scholar 

  38. Morra, M. On the molecular basis of fouling resistance. J. Biomater. Sci. Polym. Ed. 11, 547–569 (2000).

    Article  CAS  PubMed  Google Scholar 

  39. Drumheller, P. D. & Hubbell, J. A. J. Densely crosslinked polymer networks of poly(ethylene glycol) in trimethylolpropane triacrylate for cell-adhesion-resistant surfaces. Biomed. Mater. Res. 29, 207–215 (1995).

    Article  CAS  Google Scholar 

  40. Gjorevski, N. & Lutolf, M. P. Synthesis and characterization of well-defined hydrogel matrices and their application to intestinal stem cell and organoid culture. Nat. Protoc. 12, 2263–2274 (2017).

    Article  CAS  PubMed  Google Scholar 

  41. Kominami, K. et al. The molecular mechanism of apoptosis upon caspase-8 activation: quantitative experimental validation of a mathematical model. Biochim. Biophys. Acta 1823, 1825–1840 (2012).

    Article  CAS  PubMed  Google Scholar 

  42. Tummers, B. & Green, D. R. Caspase-8; regulating life and death. Immunol. Rev. 277, 76–89 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  43. Swartzlander, M. D., Lynn, A. D., Blakney, A. K., Kyriakides, T. R. & Bryant, S. J. Understanding the host response to cell-laden poly(ethylene glycol)-based hydrogels. Biomaterials 34, 952–964 (2013).

    Article  CAS  PubMed  Google Scholar 

  44. Qazi, T. H. et al. Cell therapy to improve regeneration of skeletal muscle injuries. J. Cachexia Sarcopenia Muscle 10, 501–516 (2019).

    Article  PubMed  PubMed Central  Google Scholar 

  45. Yin, H., Price, F. & Rudnicki, M. A. Satellite cells and the muscle stem cell niche. Physiol. Rev. 93, 23–67 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  46. Cerletti, M. et al. Highly efficient, functional engraftment of skeletal muscle stem cells in dystrophic muscles. Cell 134, 37–47 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  47. Rossi, C. A. et al. In vivo tissue engineering of functional skeletal muscle by freshly isolated satellite cells embedded in a photopolymerizable hydrogel. FASEB J. 25, 2296–2304 (2011).

    Article  CAS  PubMed  Google Scholar 

  48. Chapman, M. A., Meza, R. & Lieber, R. L. Skeletal muscle fibroblasts in health and disease. Differentiation 92, 108–115 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  49. Mendias, C. L. Fibroblasts take the centre stage in human skeletal muscle regeneration. J. Physiol. 595, 5005 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  50. Murphy, M. M., Lawson, J. A., Mathew, S. J., Hutcheson, D. A. & Kardon, G. Satellite cells, connective tissue fibroblasts and their interactions are crucial for muscle regeneration. Development 138, 3625–3637 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  51. Urciuolo, A. et al. Decellularised skeletal muscles allow functional muscle regeneration by promoting host cell migration. Sci. Rep. 8, 8398 (2018).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  52. Rossi, G., Manfrin, A. & Lutolf, M. P. Progress and potential in organoid research. Nat. Rev. Genet. 19, 671–687 (2018).

    Article  CAS  PubMed  Google Scholar 

  53. Foster, A. A., Marquardt, L. M. & Heilshorn, S. C. The diverse roles of hydrogel mechanics in injectable stem cell transplantation. Curr. Opin. Chem. Eng. 15, 15–23 (2017).

    Article  PubMed  Google Scholar 

  54. Hoover, E. E. & Squier, J. A. Advances in multiphoton microscopy technology. Nat. Photonics 7, 93–101 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  55. Horton, N. G. et al. In vivo three-photon microscopy of subcortical structures within an intact mouse brain. Nat. Photonics 7, 205–209 (2013).

    Article  CAS  PubMed Central  Google Scholar 

  56. Delrot, P., Loterie, D., Psaltis, D. & Moser, C. Single-photon three-dimensional microfabrication through a multimode optical fiber. Opt. Express 26, 1766–1778 (2018).

    Article  CAS  PubMed  Google Scholar 

  57. Chu, W. et al. Centimeter-height 3D printing with femtosecond laser two-photon polymerization. Adv. Mater. Technol. 3, 1700396 (2018).

    Article  CAS  Google Scholar 

  58. Schultz, S. R., Copeland, C. S., Foust, A. J., Quicke, P. & Schuck, R. Advances in two-photon scanning and scanless microscopy technologies for functional neural circuit imaging. Proc. IEEE Inst. Electr. Electron. Eng. 105, 139–157 (2017).

    Article  CAS  PubMed  Google Scholar 

  59. Horváth, O. P. Minimal invasive surgery. Acta Chir. Hung. 36, 130–131 (1997).

    PubMed  Google Scholar 

  60. Palep, J. H. Robotic assisted minimally invasive surgery. J. Minim. Access Surg. 5, 1–7 (2009).

    Article  PubMed  PubMed Central  Google Scholar 

  61. Sims, G. E. C. & Snape, T. J. A method for the estimation of polyethylene glycol in plasma protein fractions. Anal. Biochem. 107, 60–63 (1980).

    Article  CAS  PubMed  Google Scholar 

  62. Habeeb, A. F. S. A. Determination of free amino groups in proteins by trinitrobenzenesulfonic acid. Anal. Biochem. 14, 328–336 (1966).

    Article  CAS  PubMed  Google Scholar 

  63. Natarajan, D. et al. Lentiviral labeling of mouse and human enteric nervous system stem cells for regenerative medicine studies. Neurogastroenterol. Motil. 26, 1513–1518 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  64. Urcuiolo, A. et al. Collagen VI regulates satellite cell self-renewal and muscle regeneration. Nat. Commun. 4, 1964 (2013).

    Article  CAS  Google Scholar 

  65. Jung, P. et al. Isolation and in vitro expansion of human colonic stem cells. Nat. Med. 17, 1225–1227 (2011).

    Article  CAS  PubMed  Google Scholar 

  66. Sato, T. et al. Long-term expansion of epithelial organoids from human colon, adenoma, adenocarcinoma, and Barrett’s epithelium. Gastroenterology 141, 1762–1772 (2011).

    Article  CAS  PubMed  Google Scholar 

  67. Ajduk, A., Biswas Shivhare, S. & Zernicka-Goetz, M. The basal position of nuclei is one pre-requisite for asymmetric cell divisions in the early mouse embryo. Dev. Biol. 392, 133–140 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

This work was supported by 2017 STARS-WiC grant of University of Padova, Progetti di Eccellenza CaRiPaRo, TWINING of University of Padova, Oak Foundation Award (grant no. W1095/OCAY-14-191), ‘Consorzio per la Ricerca Sanitaria’ (CORIS) of the Veneto Region, Italy (LifeLab Program) to N.E. and the STARS Starting Grant 2017 of University of Padova (grant code LS3-19613) to A.U. P.D.C. is supported by the National Institute for Health Research (NIHR; grant no. NIHR-RP-2014-04-046). G.G.G. was supported by the NIHR Great Ormond Street Hospital Biomedical Research Centre Catalyst Fellowship. G.G.G., P.D.C. and N.E. were supported by the Oak award W1095/OCAY-14-191. All research at Great Ormond Street Hospital NHS Foundation Trust and University College London Great Ormond Street Institute of Child Health is made possible by the NIHR Great Ormond Street Hospital Biomedical Research Centre. The views expressed are those of the author(s) and not necessarily those of the National Health Service, the NIHR or the Department of Health. We thank D. Moulding for technical support and S. Schiaffino for scientific advice and discussion.

Author information

Authors and Affiliations

  1. Department of Industrial Engineering, University of Padova, Padova, Italy

    Anna Urciuolo, Luca Brandolino, Cecilia Laterza, Monica Giomo & Nicola Elvassore

  2. Veneto Institute of Molecular Medicine, Padova, Italy

    Anna Urciuolo, Luca Brandolino, Paolo Raffa, Valentina Scattolini, Cecilia Laterza, Laura Brigo & Nicola Elvassore

  3. Department of Women’s and Children’s Health, University of Padova, Padova, Italy

    Anna Urciuolo, Paolo Raffa, Valentina Scattolini & Elisa Zambaiti

  4. ONYEL Biotech, Padova, Italy

    Ilaria Poli

  5. University College London Great Ormond Street Institute of Child Health, London, UK

    Giovanni G. Giobbe, Giulia Selmin, Michael Magnussen, Paolo De Coppi & Nicola Elvassore

  6. Department of Specialist Paediatric and Neonatal Surgery, Great Ormond Street Hospital for Children, London, UK

    Paolo De Coppi

  7. Department of Pharmaceutical and Pharmacological Science, University of Padova, Padova, Italy

    Stefano Salmaso

  8. Shanghai Institute for Advanced Immunochemical Studies (SIAIS), ShanghaiTech University, Shanghai, China

    Nicola Elvassore

Authors
  1. Anna Urciuolo
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Ilaria Poli
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Luca Brandolino
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Paolo Raffa
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Valentina Scattolini
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Cecilia Laterza
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Giovanni G. Giobbe
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Elisa Zambaiti
    View author publications

    You can also search for this author in PubMed Google Scholar

  9. Giulia Selmin
    View author publications

    You can also search for this author in PubMed Google Scholar

  10. Michael Magnussen
    View author publications

    You can also search for this author in PubMed Google Scholar

  11. Laura Brigo
    View author publications

    You can also search for this author in PubMed Google Scholar

  12. Paolo De Coppi
    View author publications

    You can also search for this author in PubMed Google Scholar

  13. Stefano Salmaso
    View author publications

    You can also search for this author in PubMed Google Scholar

  14. Monica Giomo
    View author publications

    You can also search for this author in PubMed Google Scholar

  15. Nicola Elvassore
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

A.U. and N.E. designed the experiments. N.E. designed the photochemistry, I.P. synthesized and chemically characterized the coumarin polymers and S.S. contributed to the chemical characterization of coumarin polymers. A.U. performed and analysed in vitro and in vivo experiments. L.Brandolino. and P.R. contributed to in vitro experiments. V.S. contributed to the analysis of in vivo experiments. C.L. performed hydrogel injection into the brain and derived reporter cells and human ES cell-derived NSCs. G.G.G., E.Z., G.S. and M.M. contributed to organoid experiments. G.G. and P.D.C. characterized human intestinal organoid cultures. L.Brigo. contributed to the design and interpretation of in vitro two-photon crosslinking experiments. M.G. performed AFM analysis. A.U. and N.E. analysed the data and wrote the manuscript. N.E. supervised the project.

Corresponding author

Correspondence to Nicola Elvassore.

Ethics declarations

Competing interests

N.E. has an equity stake in ONYEL Biotech s.r.l. A.U. and N.E. are submitting a patent for the intravital 3D bioprinting (provisional patent number 102020000008779).

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary methods, figures, tables and video captions.

Reporting Summary

Supplementary Video 1

3D projection of z-stack images showing a ‘LIFE’-shaped HCC–4-arm PEG 3D structure related to Supplementary Fig. 12c.

Supplementary Video 2

3D reconstruction of z-stack images showing an empty cuboidal-shaped HCC–8-arm PEG 3D structure related to Supplementary Fig. 12e.

Supplementary Video 3

3D reconstruction of z-stack images showing a flower-shaped HCC–gel 3D structure related to Fig. 3d.

Supplementary Video 4

3D reconstruction of z-stack images showing the maximum fabrication depth related to Fig. 3e.

Supplementary Video 5

Orthogonal 3D reconstruction of z-stack images showing a cell-laden bioprinted structure related to Supplementary Fig. 18a.

Supplementary Video 6

Long-term 3D culture of MuSCs related to Fig. 4g.

Supplementary Video 7

3D reconstruction of z-stack images showing object fabricated into a drop of HCC–gel/Matrigel related to Fig. 5a.

Supplementary Video 8

3D reconstruction of z-stack images showing objects fabricated into a drop of HCC–gel/Matrigel in respect to hSIOs related to Supplementary Fig. 20a.

Supplementary Video 9

Intravital imaging related to Fig. 6b.

Supplementary Video 10

Intravital imaging related to Fig. 6e.

Supplementary Video 11

3D reconstruction related to Fig. 6e.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Urciuolo, A., Poli, I., Brandolino, L. et al. Intravital three-dimensional bioprinting. Nat Biomed Eng 4, 901–915 (2020). https://doi.org/10.1038/s41551-020-0568-z

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41551-020-0568-z

This article is cited by

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing