Multifunctional material platforms for neural interfaces: active orchestration of dynamic foreign body response across implantation lifetimes

The sustained reliability of invasive brain-computer interface (BCI) electrodes is fundamentally constrained by progressive interface destabilization, a process driven by the dynamic foreign body response (FBR). Given the intricate, time-dependent evolution of the FBR, the establishment of long-term stable neural interfaces necessitates the deployment of sophisticated material architectures capable of intercepting core regulatory mechanisms across distinct pathological phases. This review synthesizes bio-inspired and functional material design strategies, systematically examining their capacity to actively modulate the FBR in a stage-specific manner. Specifically, these approaches are engineered to attenuate acute inflammatory cascades, which is hypothesized to impede detrimental glial scarring-while establishing robust biological barriers resilient to chronic biofouling and infection. Furthermore, by mitigating material degradation and micromotion-induced fretting, these strategies are associated with preserved the functional integrity of the interface over extended periods. By consolidating the theoretical principles, recent advancements, and persisting challenges associated with these material paradigms, this work aims to delineate a forward-looking framework for the development of ultra-durable BCI electrodes, thereby accelerating the clinical translation of neural interface technologies.