Injured peripheral nerves typically exhibit unsatisfactory and incomplete functional outcomes, and there are no clinically approved therapies for improving regeneration. Post-operative electrical stimulation (ES) increases axon regrowth, but practical challenges, from the cost of extended operating room time to the risks and pitfalls associated with transcutaneous wire placement, have prevented broad clinical adoption. This study presents a possible solution in the form of advanced bioresorbable materials for a type of thin, flexible, wireless implant that provides precisely controlled ES of the injured nerve for a brief time in the immediate post-operative period. Afterward, rapid, complete, and safe modes of bioresorption naturally and quickly eliminate all of the constituent materials in their entirety, without the need for surgical extraction. The unusually high rate of bioresorption follows from the use of a unique, bilayer enclosure that combines two distinct formulations of a biocompatible form of polyanhydride as an encapsulating structure, to accelerate the resorption of active components and confine fragments until complete resorption. Results from mouse models of tibial nerve transection with re-anastomosis indicate that this system offers levels of performance and efficacy that match those of conventional wired stimulators, but without the need to extend the operative period or to extract the device hardware.
Bibliographical noteFunding Information:
H.G., D.D., and J.Z. contributed equally to this work. The authors specially thank Nayereh Ghoreishi‐Haack, Elizabeth Dempsey, Keith Bailey, Iwona Stepien, and Chad Haney for the help in biocompatibility study and imaging. This work made use of the NUFAB facility of Northwestern University's NUANCE Center, which has received support from the SHyNE Resource (NSF ECCS‐1542205), the IIN, and Northwestern's MRSEC program (NSF DMR‐1720139). This work made use of the MatCI Facility supported by the MRSEC program of the National Science Foundation (DMR‐1720139) at the Materials Research Center of Northwestern University. Imaging work was performed at the Northwestern University Center for Advanced Molecular Imaging generously supported by NCI CCSG P30 CA060553 awarded to the Robert H Lurie Comprehensive Cancer Center. R.L. gratefully acknowledges the support from the National Natural Science Foundation of China (grant nos. 12022209 and 11972103) and Liaoning Revitalization Talents Program (Grant XLYC1807126). Z.X. acknowledges the support from the National Natural Science Foundation of China (grant no. 12072057) and Fundamental Research Funds for the Central Universities (grant no. DUT20RC(3)032). Y.H. acknowledges support from NSF (grant no. CMMI1635443). This work was supported by the Querrey Simpson Institute for Bioelectronics at Northwestern University and the Belle Carnell Regenerative Neurorehabilitation Fund at Shirley Ryan AbilityLab.
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All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics