Surface modification of neural electrodes with a pyrrole-hyaluronic acid conjugate to attenuate reactive astrogliosis in vivo

Abstract

Surfaces of neural probes were electrochemically modified with a non-cell adhesive and biocompatible conjugate, pyrrole-hyaluronic acid (PyHA), to reduce reactive astrogliosis. Poly(PyHA)-modified wire electrodes were implanted into rat motor cortices for three weeks and were found to markedly reduce the expression of glial fibrillary acidic protein compared to uncoated electrodes.

A Materials Roadmap to Functional Neural Interface Design

“…[443, 448] Various PEG, poly(OEGMA), and hyaluronic acid hydrophilic coatings have been incorporated onto neural probes to prevent fouling and gliosis in vitro and in vivo . [267, 449–450] As an added benefit, hydrophilic or zwitterionic polymer chains can also sterically prevent adsorption and adhesion. [267, 451–452] Unsurprisingly, coatings are more effective in preventing gliosis in vivo if they are applied to the whole penetrating shank as opposed to just the electrode sites, however electrode site coatings can suppress increases in impedance after initial implantation.…”

“…[267, 451–452] Unsurprisingly, coatings are more effective in preventing gliosis in vivo if they are applied to the whole penetrating shank as opposed to just the electrode sites, however electrode site coatings can suppress increases in impedance after initial implantation. [450, 452]…”

A critical review of cell culture strategies for modelling intracortical brain implant material reactions

“…This can produce disparity between the phenomenon observed in vitro in regards to neuron attachment and neurite outgrowth and the in vivo reaction to the material. For example, a silicon nitride substrate coated with PLL improves PC12 cell attachment and neurite outgrowth [142], however, it is well established that the glial scarring reaction to silicon in vivo is significant [156].…”

Introducing a biomimetic coating for graphene neuroelectronics: toward in-vivo applications

“…25 In addition with these many advantages, both the thickness and biodegradation rate of HA coatings can be controlled in order to maintain a close and tiny contact with cells for an efficient recording. Until now, some examples of HA-coated electrodes have been tested in-vivo 26 or in-vitro with platinium, iridium microwires and silicon microelectrodes. 27,28 The challenge here lies in the maintenance of electrodes performances after the coating process.…”