Regenerative Electrode Interfaces for Neural Prostheses

Abstract

Neural prostheses are electrode arrays implanted in the nervous system that record or stimulate electrical activity in neurons. Rapid growth in the use of neural prostheses in research and clinical applications has occurred in recent years, but instability and poor patency in the tissue-electrode interface undermines the longevity and performance of these devices. The application of tissue engineering strategies to the device interface is a promising approach to improve connectivity and communication between implanted electrodes and local neurons, and several research groups have developed new and innovative modifications to neural prostheses with the goal of seamless device-tissue integration. These approaches can be broadly categorized based on the strategy used to maintain and regenerate neurons at the device interface: (1) redesign of the prosthesis architecture to include finer-scale geometries and/or provide topographical cues to guide regenerating neural outgrowth, (2) incorporation of material coatings and bioactive molecules on the prosthesis to improve neuronal growth, viability, and adhesion, and (3) inclusion of cellular grafts to replenish the local neuron population or provide a target site for reinnervation (biohybrid devices). In addition to stabilizing the contact between neurons and electrodes, the potential to selectively interface specific subpopulations of neurons with individual electrode sites is a key advantage of regenerative interfaces. In this study, we review the development of regenerative interfaces for applications in both the peripheral and central nervous system. Current and future development of regenerative interfaces has the potential to improve the stability and selectivity of neural prostheses, improving the patency and resolution of information transfer between neurons and implanted electrodes.

Alterations in Ion Channel Expression Surrounding Implanted Microelectrode Arrays in the Brain

“…This technique can be implemented to not only guide next-generation device designs (e.g., architecture, size, flexibility, surface chemistry/topography 9,44-47 ), but also intervention strategies (e.g., coatings, microfluidic delivery, etc. [82][83][84][85] ) aimed at improving long-term recording quality.…”

The Pursuit of Chronically Reliable Neural Interfaces: A Materials Perspective

“…As a result, numerous flexible and stretchable microelectrode arrays have emerged, first as surface interfaces (Figure 1C) and later coming up with intracortical probes when a range of insertion mechanisms were developed (Patil and Thakor, 2016). More recently, the concept of regenerative neural interfaces is being revived, combining state-of-the-art stretchable electronics with tissue engineering approaches for a better-integrated electrode-tissue interface (Figure 1D; Lacour et al, 2010; Clements et al, 2013; Musick et al, 2015; Srinivasan et al, 2015; Thompson et al, 2016). All these moves manifest the pursuit of a biomimicry strategy from the mechanical aspect under the indistinguishability principle.…”

“…The indistinguishability principle can be further applied by biochemical modification to the limited amount device materials. For the second requirement, the biomimicry engineering strategy is embodied in the design of regenerative neural interfaces for a more effective electrode–neuron integration through the creation of either tissue regeneration scaffolds in which micro neural electrodes are embedded (Figure 1D; Lacour et al, 2010; Clements et al, 2013; Musick et al, 2015; Srinivasan et al, 2015; Thompson et al, 2016) or muscle graft relays for guiding the deeply embedded neural signal sources to engineered structures for easily probing (French et al, 2014; Martin, 2015). These regenerative neural interfaces also manifest the need for dual-side engineering in order to create a better-integrated electrode-tissue interface, where tissue engineering and biomaterials can play a significant role in engineering the biologic side.…”

A model of electrical impedance tomography implemented in nerve-cuff for neural-prosthetics control

“…Among neural interface technologies a trade-off exists between beneficial characteristics, with no single device achieving high chronic stability, a high number of control channels (selectivity) and low invasiveness (Ortiz-Catalan, Brånemark et al 2012, del Valle and Navarro 2013, Thompson, Zoratti et al 2016. Nerve cuffs are the least invasive and least selective peripheral nerve interface.…”