Topological Hydrogels for Long-Term Brain Signal Monitoring, Neuromodulation, and Stroke Treatment.

Stroke is the primary cause of disability without effective rehabilitation methods. Emerging brain-machine interfaces offer promise for regulating brain neural circuits and promoting the recovery of brain function disorders. Implantable probes play key roles in brain-machine interfaces, which are subject to two irreconcilable tradeoffs between conductivity and modulus match/transparency. In this work, we incorporated mechanically interlocked polyrotaxane in topological hydrogels to solve the two tradeoffs at the molecular level through the pulley effect of polyrotaxane. The unique performance of the topological hydrogels enabled them to acquire brain neural information and conduct neuromodulation. The probe was capable of continuously recording local field potentials for 8 weeks. Optogenetic neuromodulation in the primary motor cortex to regulate brain neural circuits and control limb behavior was realized using the probe. Most importantly, optogenetic neuromodulation was conducted using the probe, which effectively reduced the infarct regions of the brain tissue and promoted locomotor function recovery. This work exhibits a significant scientific advancement in the design concept of neural probes for developing brain-machine interfaces and seeking brain disease therapies. This article is protected by copyright. All rights reserved.