Film-based Implants for Supporting Neuron-Electrode Integrated Interfaces for The Brain

Area of Science:

• Neural Engineering
• Biomaterials Science
• Neuroscience

Background:

• Brain-machine interfaces (BMIs) offer potential for modulating neural functions.
• Long-term BMIs face challenges with graft cell survival and electrode sensitivity.
• Silk films present a promising substrate for neural implants due to their biocompatibility and mechanical properties.

Purpose of the Study:

• To develop integrated neuron-electrode interfaces on flexible silk films for brain implants.
• To optimize silk film properties for enhanced cell survival and neural circuit integration.
• To evaluate the performance and biocompatibility of these implants in vivo.

Main Methods:

• Silk films were fabricated with optimized mechanical properties and surface topography.
• Primary rat cortical cells were cultured and aligned on silk films.
• Compartmentalized neural circuits and electrode arrays were integrated onto the silk films.
• Electrical stimulation and calcium imaging were used to assess neural activity.
• Silk film implants were tested in mice brains to evaluate biocompatibility and stability.

Main Results:

• Optimized silk films promoted survival and alignment of cortical neurons.
• Integrated neuron-electrode interfaces on silk films demonstrated electrical stimulation capabilities.
• Silk film implants in mice showed conformal contact, modulated host brain cells, and exhibited minimal inflammation.
• Stable indwelling of implants was observed for several weeks.

Conclusions:

• Integrated silk film implants offer a viable approach for sustained functional brain-machine interfaces.
• Combining cell therapy with brain electrodes on silk films enables precise ex vivo control of neural activity.
• This technology holds promise for advanced neural prosthetics and therapeutic interventions.