In Vivo Chronic Brain Cortex Signal Recording Based on a Soft Conductive Hydrogel Biointerface

Area of Science:

• Neuroscience
• Biomaterials Science
• Bioelectronics

Background:

• Acquiring neural signals is vital for understanding brain function, diagnosing disorders, and developing brain-computer interfaces.
• Current neural interfaces face challenges with biocompatibility, leading to tissue damage and signal degradation, limiting long-term use.

Purpose of the Study:

• To design and create a novel, soft neural biointerface with enhanced biocompatibility and recording capabilities.
• To address the limitations of existing neural interfaces by improving conformability and reducing foreign body response.

Main Methods:

• Fabrication of a novel polyacrylamide hydrogel neural biointerface incorporating plasmonic silver nanocubes.
• Integration of a silicon-based template for stable neural-hydrogel contact and precise recording site targeting.
• In vitro cell culture studies with neural progenitor cells to assess biocompatibility and neuronal differentiation.
• In vivo chronic neuroinflammation tests in a mouse model.
• Electrocorticography (ECoG) recordings for evaluating long-term neural signal acquisition.

Main Results:

• The nanostructured hydrogels exhibited superior electroconductivity and mechanical properties mimicking brain tissue.
• In vitro tests confirmed the hydrogel's biocompatibility and ability to promote neuronal differentiation.
• In vivo studies showed no adverse immune response to the nanostructured hydrogel interface.
• The platform facilitated long-term, efficient electrocorticography recordings of neural signals.

Conclusions:

• The novel nanostructured hydrogel neural biointerface demonstrates excellent biocompatibility and long-term performance.
• This technology offers a promising solution for chronic neural recording and advanced brain-computer interfaces.
• The developed interface minimizes tissue damage and immune response, paving the way for permanent neural implants.