Bioactive polymer-enabled conformal neural interface and its application strategies

Abstract

Neural interface is a powerful tool to control the varying neuron activities in brain, where the performance can directly affect the quality of recording neural signals and the reliability of...

Challenges and Opportunities of Implantable Neural Interfaces: From Material, Electrochemical and Biological Perspectives

“…[197] In particular, nature-derived and biodegradable materials such as polypeptides (e.g., silk, collagen), extracellular matrix (ECM), polysaccharides (e.g., chitin, chitosan), etc., have been widely applied as functional components on biomedical science due to their biodegradability, bioconformability, and stimuli response. [2,197,198]…”

“…[202] Using SF to construct neural electrodes requires degumming and regeneration of raw silk, followed by solvent evaporation to be processed into films or coating layers. [2] Cointe et al [203] presented an ultrathin and flexible probe consisting of a silk-parylene bilayer with programmable degradation time (Figure 10A). They successfully delivered parylene probes as thin as 4 μm to a desired depth in the brain with minimal rejection, and intact geometry and electrical functionality.…”

“…[ 1 ] Neural interface technologies improve our understanding of the nervous system. [ 2 ] Commendably, this enables the treatment of neurological diseases such as epilepsy, Parkinson's disease, deafness, blindness, and so on, which is expected to significantly reduce their socioeconomic burden globally. [ 3 ] In the last few decades, we have witnessed the rapid development of neural interfaces, and some typical implantable microelectrodes have been successfully applied to humans, including neural electrodes for retinal prostheses, [ 4 ] cochlear implants, [ 5 ] deep brain stimulation (DBS), [ 6 ] etc.…”

Simultaneous Presentation of Dexamethasone and Nerve Growth Factor via Layered Carbon Nanotubes and Polypyrrole to Interface Neural Cells

“…The insertion of neural electrodes into the brain tissue unavoidably disrupts the blood-brain barrier, damages blood vessels, and causes the death of neural cells around the electrodes, leading to acute inflammatory reactions characterized as the release of inflammatory factors and activation of microglia cells and astrocytes . An insulating coating with a thickness of 50–100 μm composed of reactive astrocytes and glial cells will be formed surrounding the implanted electrode . The glial insulating coating increases the distance between the active electrode site and the neural tissue, inhibits the axon regrowth toward the electrode sites, and leads to the elevation of interface impedance, causing a decrease or even failure of long-term working capabilities …”

“…8 An insulating coating with a thickness of 50−100 μm composed of reactive astrocytes and glial cells will be formed surrounding the implanted electrode. 9 The glial insulating coating increases the distance between the active electrode site and the neural tissue, inhibits the axon regrowth toward the electrode sites, and leads to the elevation of interface impedance, causing a decrease or even failure of long-term working capabilities. 10 Various strategies have been developed to improve the longterm and high-performance neural signal recording/stimulation, such as using soft electrode materials, surface coating with conductive polymers, local release or presentation of antiinflammatory drugs, or neural growth promoted biomolecules.…”