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Rapid prototyping of soft bioelectronic implants for use as neuromuscular interfaces

Abstract

Neuromuscular interfaces are required to translate bioelectronic technologies for application in clinical medicine. Here, by leveraging the robotically controlled ink-jet deposition of low-viscosity conductive inks, extrusion of insulating silicone pastes and in situ activation of electrode surfaces via cold-air plasma, we show that soft biocompatible materials can be rapidly printed for the on-demand prototyping of customized electrode arrays well adjusted to specific anatomical environments, functions and experimental models. We also show, with the monitoring and activation of neuronal pathways in the brain, spinal cord and neuromuscular system of cats, rats and zebrafish, that the printed bioelectronic interfaces allow for long-term integration and functional stability. This technology might enable personalized bioelectronics for neuroprosthetic applications.

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Fig. 1: Rapid prototyping of soft electrode implants for interfacing the neuromuscular system.
Fig. 2: Printing and mechanical properties of planar electrode arrays.
Fig. 3: Electromechanical properties.
Fig. 4: Neuromodulation of the locomotor circuitry using NeuroPrint technology.
Fig. 5: Multi-nodal activation and monitoring of the neuromuscular system using NeuroPrint technology.
Fig. 6: Biointegration of NeuroPrint electrode arrays.
Fig. 7: Functional stability of NeuroPrint electrode arrays.

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Data availability

The main data supporting the results in this study are available within the paper and its Supplementary Information file. The raw and analysed datasets generated during the study are too large to be publicly shared, but they are available for research purposes from the corresponding authors on reasonable request.

Code availability

The code used to program the printer paths can be found at https://sourceforge.net/projects/g-code-processor.

References

  1. Wagner, F. B. et al. Targeted neurotechnology restores walking in humans with spinal cord injury. Nature 563, 65–71 (2018).

    CAS  PubMed  Google Scholar 

  2. Granata, G. et al. Phantom somatosensory evoked potentials following selective intraneural electrical stimulation in two amputees. Clin. Neurophysiol. 129, 1117–1120 (2018).

    PubMed  Google Scholar 

  3. Ajiboye, A. B. et al. Restoration of reaching and grasping movements through brain-controlled muscle stimulation in a person with tetraplegia: a proof-of-concept demonstration. Lancet 389, 1821–1830 (2017).

    PubMed  PubMed Central  Google Scholar 

  4. Liu, Y. et al. Soft and elastic hydrogel-based microelectronics for localized low-voltage neuromodulation. Nat. Biomed. Eng. 3, 58–68 (2019).

    CAS  PubMed  Google Scholar 

  5. Minev, I. R. et al. Electronic dura mater for long-term multimodal neural interfaces. Science 347, 159–163 (2015).

    CAS  PubMed  Google Scholar 

  6. Fu, T.-M., Hong, G., Viveros, R. D., Zhou, T. & Lieber, C. M. Highly scalable multichannel mesh electronics for stable chronic brain electrophysiology. Proc. Natl Acad. Sci. USA 114, E10046–E10055 (2017).

    CAS  PubMed  PubMed Central  Google Scholar 

  7. Boutry, C. M. et al. A stretchable and biodegradable strain and pressure sensor for orthopaedic application. Nat. Electron. 1, 314–321 (2018).

    Google Scholar 

  8. Kim, T.-i et al. Injectable, cellular-scale optoelectronics with applications for wireless optogenetics. Science 340, 211–216 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  9. Reeder, J. et al. Mechanically adaptive organic transistors for implantable electronics. Adv. Mater. 26, 4967–4973 (2014).

    CAS  PubMed  Google Scholar 

  10. Lu, C. et al. Flexible and stretchable nanowire-coated fibers for optoelectronic probing of spinal cord circuits. Sci. Adv. https://doi.org/10.1126/sciadv.1600955 (2017).

  11. Sengeh, D. M. & Herr, H. A variable-impedance prosthetic socket for a transtibial amputee designed from magnetic resonance imaging data. J. Prosthet. Orthot. 25, 129–137 (2013).

    Google Scholar 

  12. Filardo, G. et al. Novel alginate biphasic scaffold for osteochondral regeneration: an in vivo evaluation in rabbit and sheep models. J. Mater. Sci. Mater. Med. 29, 74 (2018).

    PubMed  Google Scholar 

  13. Ploch, C. C., Mansi, C. S., Jayamohan, J. & Kuhl, E. Using 3D printing to create personalized brain models for neurosurgical training and preoperative planning. World Neurosurg. 90, 668–674 (2016).

    PubMed  Google Scholar 

  14. Valentine, A. D. et al. Hybrid 3D printing of soft electronics. Adv. Mater. 29, 1703817 (2017).

    Google Scholar 

  15. Lind, J. U. et al. Instrumented cardiac microphysiological devices via multimaterial three-dimensional printing. Nat. Mater. 16, 303–308 (2017).

    CAS  PubMed  Google Scholar 

  16. Bachmann, B. et al. All-inkjet-printed gold microelectrode arrays for extracellular recording of action potentials. Flex. Print. Electron. 2, 035003 (2017).

    Google Scholar 

  17. Athanasiadis, M. et al. Printed elastic membranes for multimodal pacing and recording of human stem-cell-derived cardiomyocytes. npj Flex. Electron. https://doi.org/10.1038/s41528-020-0075-z (2020).

  18. Minev, I. R., Wenger, N., Courtine, G. & Lacour, S. P.Research update: platinum-elastomer mesocomposite as neural electrode coating.APL Mater. 3, 014701 (2015).

    Google Scholar 

  19. Mo, L. et al. Nano-silver ink of high conductivity and low sintering temperature for paper electronics. Nanoscale Res. Lett. 14, 197 (2019).

    PubMed  PubMed Central  Google Scholar 

  20. Van Noort, R., Black, M. M., Martin, T. R. P. & Meanley, S. A study of the uniaxial mechanical properties of human dura mater preserved in glycerol. Biomaterials 2, 41–45 (1981).

    CAS  PubMed  Google Scholar 

  21. Kwan, M. K., Wall, E. J., Massie, J. & Garfin, S. R. Strain, stress and stretch of peripheral nerve rabbit experiments in vitro and in vivo. Acta Orthop. Scand. 63, 267–272 (1992).

    CAS  PubMed  Google Scholar 

  22. Calvo, B. et al. Passive nonlinear elastic behaviour of skeletal muscle: experimental results and model formulation. J. Biomech. 43, 318–325 (2010).

    CAS  PubMed  Google Scholar 

  23. Nicholson, K. J. & Winkelstein, B. A. in Neural Tissue Biomechanics (ed. Bilston, L. E.) 203–229 (Springer, 2011).

  24. Harrison, D. E., Cailliet, R., Harrison, D. D., Troyanovich, S. J. & Harrison, S. O. A review of biomechanics of the central nervous system—part II: spinal cord strains from postural loads. J. Manipulative Physiol. Ther. 22, 322–332 (1999).

    CAS  PubMed  Google Scholar 

  25. Diani, J., Fayolle, B. & Gilormini, P. A review on the Mullins effect. Eur. Polym. J. 45, 601–612 (2009).

    CAS  Google Scholar 

  26. Neto, J. P. et al. Does impedance matter when recording spikes with polytrodes? Front. Neurosci. https://doi.org/10.3389/fnins.2018.00715 (2018).

  27. Cogan, S. F. Neural stimulation and recording electrodes. Annu. Rev. Biomed. Eng. 10, 275–309 (2008).

    CAS  PubMed  Google Scholar 

  28. Biegler, T. An electrochemical and electron microscopic study of activation and roughening of platinum electrodes. J. Electrochem. Soc. 116, 1131 (1969).

    CAS  Google Scholar 

  29. Tondera, C. et al. Highly conductive, stretchable, and cell-adhesive hydrogel by nanoclay doping. Small 15, 1901406 (2019).

    Google Scholar 

  30. Won, S. M. et al. Recent advances in materials, devices, and systems for neural interfaces. Adv. Mater. 30, 1800534 (2018).

    Google Scholar 

  31. Capogrosso, M. et al. A brain–spine interface alleviating gait deficits after spinal cord injury in primates. Nature 539, 284–288 (2016).

    PubMed  PubMed Central  Google Scholar 

  32. Musienko, P. E. et al. Spinal and supraspinal control of the direction of stepping during locomotion. J. Neurosci. 32, 17442–17453 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  33. Harkema, S. et al. Effect of epidural stimulation of the lumbosacral spinal cord on voluntary movement, standing, and assisted stepping after motor complete paraplegia: a case study. Lancet 377, 1938–1947 (2011).

    PubMed  PubMed Central  Google Scholar 

  34. Courtine, G. et al. Transformation of nonfunctional spinal circuits into functional states after the loss of brain input. Nat. Neurosci. 12, 1333–1342 (2009).

    CAS  PubMed  PubMed Central  Google Scholar 

  35. Wenger, N. et al. Spatiotemporal neuromodulation therapies engaging muscle synergies improve motor control after spinal cord injury. Nat. Med. 22, 138–145 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  36. Hoffman, P.Beitrage zur kenntnis der menschlichen reflexe mit besonderer berucksichtigung der elektrischen erscheinungen.Arch. F. Physiol. 1, 223–256 (1910).

    Google Scholar 

  37. Shik, M. L. Control of walking and running by means of electrical stimulation of the midbrain. Biofizika 11, 659–666 (1966).

    CAS  PubMed  Google Scholar 

  38. Fry, C. H., Wu, C. & Sui, G. P. Electrophysiological properties of the bladder. Int. Urogynecol. J. 9, 291–298 (1998).

    CAS  Google Scholar 

  39. Liu, D. W. & Westerfield, M. Function of identified motoneurones and co-ordination of primary and secondary motor systems during zebra fish swimming. J. Physiol. 403, 73–89 (1988).

    CAS  PubMed  PubMed Central  Google Scholar 

  40. Hains, B. C. & Waxman, S. G. Activated microglia contribute to the maintenance of chronic pain after spinal cord injury. J. Neurosci. 26, 4308–4317 (2006).

    CAS  PubMed  PubMed Central  Google Scholar 

  41. Sierra, A. et al. The “Big-Bang” for modern glial biology: translation and comments on Pío del Río-Hortega 1919 series of papers on microglia.Glia 64, 1801–1840 (2016).

    PubMed  Google Scholar 

  42. Musienko, P. et al. Somatosensory control of balance during locomotion in decerebrated cat. J. Neurophysiol. 107, 2072–2082 (2012).

    PubMed  PubMed Central  Google Scholar 

  43. Nonnekes, J. et al. Neurological disorders of gait, balance and posture: a sign-based approach. Nat. Rev. Neurol. 14, 183–189 (2018).

    PubMed  Google Scholar 

  44. Musienko, P. E. et al. Neuronal control of posture and locomotion in decerebrated and spinalized animals. Ross. Fiziol. Zh. Im. I. M. Sechenova 99, 392–405 (2013).

    CAS  PubMed  Google Scholar 

  45. Gill, M. L. et al. Neuromodulation of lumbosacral spinal networks enables independent stepping after complete paraplegia. Nat. Med. https://doi.org/10.1038/s41591-018-0175-7 (2018).

  46. Kim, Y. et al. A bioinspired flexible organic artificial afferent nerve. Science 360, 998–1003 (2018).

    CAS  PubMed  Google Scholar 

  47. Vu, P. P. et al. A regenerative peripheral nerve interface allows real-time control of an artificial hand in upper limb amputees. Sci. Transl. Med. 12, eaay2857 (2020).

    PubMed  PubMed Central  Google Scholar 

  48. Vachicouras, N. et al. Microstructured thin-film electrode technology enables proof of concept of scalable, soft auditory brainstem implants. Sci. Transl. Med. 11, eaax9487 (2019).

    PubMed  Google Scholar 

  49. Borton, D. et al. Corticospinal neuroprostheses to restore locomotion after spinal cord injury. Neurosci. Res. 78, 21–29 (2014).

    PubMed  Google Scholar 

  50. Athanasiadis, M., Pak, A., Afanasenkau, D. & Minev, I. R. Direct writing of elastic fibers with optical, electrical, and microfluidic functionality. Adv. Mater. Technol. 4, 1800659 (2019).

    CAS  Google Scholar 

  51. Hudak, E. M., Mortimer, J. T. & Martin, H. B. Platinum for neural stimulation: voltammetry considerations. J. Neural Eng. 7, 026005 (2010).

    CAS  Google Scholar 

  52. Whelan, P. J. Control of locomotion in the decerebrate cat. Prog. Neurobiol. 49, 481–515 (1996).

    CAS  PubMed  Google Scholar 

  53. Shik, M. L. & Orlovsky, G. N. Neurophysiology of locomotor automatism. Physiol. Rev. 56, 465–501 (1976).

    CAS  PubMed  Google Scholar 

  54. Mori, S., Kawahara, K., Sakamoto, T., Aoki, M. & Tomiyama, T. Setting and resetting of level of postural muscle tone in decerebrate cat by stimulation of brain stem. J. Neurophysiol. 48, 737–748 (1982).

    CAS  PubMed  Google Scholar 

  55. Iwahara, T., Atsuta, Y., Garcia-Rill, E. & Skinner, R. D. Spinal cord stimulation-induced locomotion in the adult cat. Brain Res. Bull. 28, 99–105 (1992).

    CAS  PubMed  Google Scholar 

  56. Gerasimenko, Y. P. et al. Formation of locomotor patterns in decerebrate cats in conditions of epidural stimulation of the spinal cord. Neurosci. Behav. Physiol. 35, 291–298 (2005).

    PubMed  Google Scholar 

  57. Merkulyeva, N. et al. Activation of the spinal neuronal network responsible for visceral control during locomotion. Exp. Neurol. 320, 112986 (2019).

    PubMed  Google Scholar 

  58. Kruse, M. N. & de Groat, W. C. Spinal pathways mediate coordinated bladder/urethral sphincter activity during reflex micturition in decerebrate and spinalized neonatal rats. Neurosci. Lett. 152, 141–144 (1993).

    CAS  PubMed  Google Scholar 

  59. Shefchyk, S. J. & Buss, R. R. Urethral pudendal afferent-evoked bladder and sphincter reflexes in decerebrate and acute spinal cats. Neurosci. Lett. 244, 137–140 (1998).

    CAS  PubMed  Google Scholar 

  60. Gerasimenko, Y. et al. Propriospinal bypass of the serotonergic system that can facilitate stepping. J. Neurosci. 29, 5681–5689 (2009).

    CAS  PubMed  PubMed Central  Google Scholar 

  61. Westerfield, M. The Zebrafish Book. A Guide for the Laboratory Use of Zebrafish (Danio rerio) 4th edn (Univ. Oregon Press, 2000).

  62. Martins, T., Valentim, A. M., Pereira, N. & Antunes, L. M. Anaesthesia and analgesia in laboratory adult zebrafish: a question of refinement. Lab. Anim. 50, 476–488 (2016).

    CAS  PubMed  Google Scholar 

  63. Capogrosso, M. et al. Configuration of electrical spinal cord stimulation through real-time processing of gait kinematics. Nat. Protoc. 13, 2031–2061 (2018).

    CAS  PubMed  Google Scholar 

  64. Jorfi, M., Skousen, J. L., Weder, C. & Capadona, J. R. Progress towards biocompatible intracortical microelectrodes for neural interfacing applications. J. Neural Eng. 12, 011001 (2014).

    PubMed  PubMed Central  Google Scholar 

  65. Kirik, O. V., Sukhorukova, E. G. & Korzhevskiĭ, D. E. Calcium-binding Iba-1/AIF-1 protein in rat brain cells. Morfologiia 137, 5–8 (2010).

    CAS  PubMed  Google Scholar 

  66. Schindelin, J. et al. Fiji: an open-source platform for biological-image analysis. Nat. Methods 9, 676–682 (2012).

    CAS  PubMed  Google Scholar 

  67. Kreutzberg, G. W. Microglia: a sensor for pathological events in the CNS. Trends Neurosci. 19, 312–318 (1996).

    CAS  PubMed  Google Scholar 

  68. Refolo, V. & Stefanova, N. Neuroinflammation and glial phenotypic changes in alpha-synucleinopathies. Front. Cell. Neurosci. https://doi.org/10.3389/fncel.2019.00263 (2019).

  69. Pistohl, T., Schulze-Bonhage, A., Aertsen, A., Mehring, C. & Ball, T. Decoding natural grasp types from human ECoG. NeuroImage 59, 248–260 (2012).

    PubMed  Google Scholar 

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Acknowledgements

We acknowledge funding from the following sources: the European Research Council (804005; IntegraBrain), Saint-Petersburg State University (project 51134206; funding to O.G. and N.M. for animal facility and biocompatibility studies, and validation of the implants on in vivo models), Technische Universität Dresden, the Russian Foundation for Basic Research (grants 20-015-00568-a (for the urodynamic study) and 18-33-20062-mol_a_ved (for developing the optimal electrode array configuration)), Deutsche Forschungsgemeinschaft (MI 2117/1-1) and the Volkswagen Foundation (Freigeist 91 690). We thank D. E. Korzhevskiy (immunohistochemistry), Y. I. Sysoev (zebrafish model), A. V. Goriainova (functional tests) and T. Kurth (electron microscopy) for help and expertise.

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Authors

Contributions

I.R.M. and P.M. conceived of and initiated the project and wrote the manuscript. D.A., D.K., C.T., O.G., N.P., I.R.M. and P.M. designed and performed the experiments. D.A., D.K., V.L., C.T., S.M., N.M., A.V.K., I.R.M. and P.M. analysed the data and contributed to writing the manuscript. P.M. and I.R.M. supervised the study.

Corresponding authors

Correspondence to Ivan R. Minev or Pavel Musienko.

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Supplementary information

Supplementary Information

Supplementary Figs. 1–18, captions for Supplementary Videos 1–3 and references.

Reporting Summary

Supplementary Video 1

Hybrid printing technology for personalized soft neuromuscular interfaces (NeuroPrint).

Supplementary Video 2

Facilitation of the spinal locomotor network by the NeuroPrint array.

Supplementary Video 3

Long-term biointegration of the NeuroPrint technology.

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Afanasenkau, D., Kalinina, D., Lyakhovetskii, V. et al. Rapid prototyping of soft bioelectronic implants for use as neuromuscular interfaces. Nat Biomed Eng 4, 1010–1022 (2020). https://doi.org/10.1038/s41551-020-00615-7

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