Understanding the Mechanobiology of Gliosis May Be the Key to Unlocking Sustained Chronic Performance of Bioelectronic Neural Interfaces

Abstract

In an effort to develop the next generation of neural implants, current research has focused on solving the challenges associated with the foreign body reaction and promoting long‐term device performance in vivo. Although the cutting edge of research in this field appears to be moving away from traditional metallic and semiconductor materials, the complex tissue dynamics which occur at the electrode–neural interface following device implantation are yet to be resolved. In particular, understanding the molecular processes of gliosis and the onset and persistence of scar formation is key in developing stable and specific neural recording/stimulation devices. Critically, it is recognized that neural device implantation leads to a significant disruption of tissue integrity at the peri‐electrode site. Accordingly, an in‐depth understanding of mechanotransduction in neuronal cell populations at the peri‐implant region is required to better inform neural interface design. This perspective highlights the need for a comprehensive mechanobiological understanding of gliosis to enhance the development of neural implants with improved chronic functionality.

Micromotion derived fluid shear stress mediates peri-electrode gliosis through mechanosensitive ion channels

“…Furthermore, a number of studies have identified a significant role of the mechanical mismatch between stiff neural probes and the soft brain composition on reactive gliosis [24,25], leading to the development of softer or mechanically adaptive neural electrodes [26][27][28][29]. In particular, a growing body of evidence shows that relative micromotion at the probe/tissue interface arising from respiration, pulsatile blood flow and physical movement [30][31][32], is a significant mediator of glial scarring [33][34][35][36][37]. These mechanical actions expose the peri-electrode tissues to cyclic shear stresses [38][39][40][41][42][43][44],…”