Multishank Thin-Film Neural Probes and Implantation System for High-Resolution Neural Recording Applications

Abstract Silicon probes have played a key role in studying the brain. However, the stark mechanical mismatch between these probes and the brain leads to chronic damage in the surrounding neural tissue, limiting their application in research and clinical translation. Mechanically flexible probes made of thin plastic shanks offer an attractive tissue‐compatible alternative but are difficult to implant into the brain. They also struggle to achieve the electrode density and layout necessary for the high‐resolution applications their silicon counterparts excel at. Here, a multishank high‐density flexible neural probe design is presented, which emulates the functionality of stiff silicon arrays for recording from neural population across multiple sites within a given region. The flexible probe is accompanied by a detachable 3D printed implanter, which delivers the probe by means of hydrophobic‐coated shuttles. The shuttles can then be retracted with minimal movement and the implanter houses the electronics necessary for in vivo recording applications. Validation of the probes through extracellular recordings from multiple brain regions and histological evidence of minimal foreign body response opens the path to long‐term chronic monitoring of neural ensembles

Inflight Fluidic Fibre Printing Towards Array and 3D Optoelectronic and Sensing Architectures

Scalability and device-integration have been prevailing issues limiting our ability in harnessing the full potential of small-diameter conducting fibres. We report inflight fluidic fibre printing, a rapid, low-cost route that integrates the entire process of conducting fibre production and fibre-to-circuit connection, in a single step under sub-100 °C ambient atmospheres. Metallic (silver) or organic (PEDOT:PSS) fibres with 1-3 μm diameter are fabricated, and the fibre arrays exhibit over 95 % transmittance in the 350-750 nm region. We exploit combinations of the unique fibre characteristics: directionality, high surface-area-to-volume ratio, and permissiveness, along with transparency and conductivity. Using PEDOT:PSS fibres as a cell-interfaced impedimetricsensor and a moisture sensor, we show that even a single fibre component can achieve complex functions or outperform conventional film-based devices. The capability to design suspended fibres and networks of homo-, hetero- cross-junctions, paves the way to applications includingflow-permissive devices, and 3D optoelectronic and sensor architectures.</div

Functional neurological restoration of amputated peripheral nerve using biohybrid regenerative bioelectronics.

The development of neural interfaces with superior biocompatibility and improved tissue integration is vital for treating and restoring neurological functions in the nervous system. A critical factor is to increase the resolution for mapping neuronal inputs onto implants. For this purpose, we have developed a new category of neural interface comprising induced pluripotent stem cell (iPSC)-derived myocytes as biological targets for peripheral nerve inputs that are grafted onto a flexible electrode arrays. We show long-term survival and functional integration of a biohybrid device carrying human iPSC-derived cells with the forearm nerve bundle of freely moving rats, following 4 weeks of implantation. By improving the tissue-electronics interface with an intermediate cell layer, we have demonstrated enhanced resolution and electrical recording in vivo as a first step toward restorative therapies using regenerative bioelectronics

Prevention of the foreign body response to implantable medical devices by inflammasome inhibition.

SignificanceImplantable electronic medical devices (IEMDs) are used for some clinical applications, representing an exciting prospect for the transformative treatment of intractable conditions such Parkinson's disease, deafness, and paralysis. The use of IEMDs is limited at the moment because, over time, a foreign body reaction (FBR) develops at the device-neural interface such that ultimately the IEMD fails and needs to be removed. Here, we show that macrophage nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome activity drives the FBR in a nerve injury model yet integration of an NLRP3 inhibitor into the device prevents FBR while allowing full healing of damaged neural tissue to occur.Part of the RNA-Seq work was performed with the Genomics and Transcriptomics Core, which is funded by the UK Medical Research Council (MRC) Metabolic Disease Unit (MRC_MC_UU_00014/5) and a Wellcome Trust Major Award (208363/Z/17/Z), and guidance from Marcella Ma, whom the authors wish to thank. CEB was supported by a Wellcome Trust Investigator award (108045/Z/15/Z). This work was also supported by the UK Wellcome Trust (Translational Medicine and Therapeutics PhD Programme Fellowship 109511/Z/15/Z to DGB), the UK Health Education England and the National Institute for Health Research (HEE/ NIHR ICA Program Clinical Lectureship CL-2019-14-004 to DGB), the UK Medical Research Council (MRC) and the Sackler Foundation (doctoral training grant RG70550 to ACL), the Engineering and Physical Sciences Research Council (EPSRC) Cambridge NanoDTC (EP/L015978/1), the Centre for Trophoblast Research (MP and RSH), the Whitaker International Scholars Program (ALR), the European Commission’s Horizon 2020 (Marie Sklodowska-Curie Fellowship 797506 to ALR), the Bertarelli Foundation (SPL), the European Research Council (Consolidator Award 772426 to KF), the UK Biotechnology and Biological Sciences Research Council (Research Grant BB/N006402/1 to KF), and the Alexander von Humboldt Foundation (Humboldt Professorship to KF)