Figure 12.

Neural interface stability can be compromised due to BBB gap formation and release of macromolecules causing an exacerbated immune response. a) Chronic neural implant failure cause chronic BBB failure, which induces a cascade of deleterious immune responses including glial scarring and neurodegeneration which results in recording failures. In general, the SNR increases over the course of the implantation, and soon after implantation the presence of reactive astrocytes is high (GFAP+, red). After 16 weeks of implantation, reactive astrocytes are still localized around the implanted electrode interface. Reproduced with permission.^[173] Copyright 2013, Elsevier. b) By employing mechanically compliant nanocomposites, the neuroinflammatory response is mitigated and recruitment of reactive astrocytes and subsequent glial scarring is reduced. Reproduced with permission.^[100] Copyright 2014, Institute of Physics.