Hydrogen sulfide as a hypoxia mimetic for improving chronic neural implant integration.

Chronic neural implants often exhibit progressive loss of function due to a foreign body response characterized by inflammation, oxidative stress, and glial scarring at the implant-tissue interface. While advances in device mechanics and materials have improved performance, complementary bioactive strategies are needed to modulate the local biological environment and enhance long-term stability. Here, we propose that hydrogen sulfide (H₂S), an endogenously produced gasotransmitter with cytoprotective, antioxidant, and neuromodulatory functions, can be leveraged as a localized hypoxia mimetic at the neural implant interface. Specifically, we advance the hypothesis that controlled, low-dose H₂S delivery can transiently engage hypoxia-responsive signaling pathways, including modulation of mitochondrial respiration, stabilization of hypoxia-inducible factor-1α, and activation of redox-sensitive transcriptional programs, to shift the foreign body response toward a more permissive, pro-survival state. This framework integrates mechanistic insights from H₂S biology with the physiological constraints of the peri-implant microenvironment, emphasizing spatial confinement, temporal control, and dose precision as key design parameters. We examine how these constraints shape potential delivery strategies and highlight the limitations of passive release approaches for achieving consistent, therapeutically relevant signaling. We further outline testable predictions and experimental pathways for evaluating this hypothesis, alongside key translational challenges including dose regulation,