Thermally Drawn Multifunctional All-Hydrogel Fibers for Anti-Fibrotic and Multimodal Neural Interfaces

Area of Science:

• Biomaterials Science
• Neuroengineering
• Materials Science

Background:

• Hydrogels offer tissue-like properties for neural interfaces, but microfabrication challenges limit multimodal applications.
• Existing neural interfaces often face limitations due to fibrotic encapsulation and lack of integrated functionalities.
• Developing compact, multifunctional neural interfaces with anti-fibrotic properties is crucial for advanced neuroscience research.

Purpose of the Study:

• To present a hydrogel thermal drawing process (HG-TDP) for co-fabricating multiple functional hydrogels into a single fiber.
• To develop compact, all-hydrogel neural interfaces that minimize tissue fibrosis and enable multimodal functions.
• To demonstrate the capability of these interfaces for neural recording, stimulation, and drug delivery.

Main Methods:

• A novel hydrogel thermal drawing process (HG-TDP) was developed to enable thermoplastic deformation and co-fabrication of multiple hydrogels.
• Key process parameters were optimized to create integrated, multifunctional hydrogel fibers.
• The developed all-hydrogel fibers were characterized for their mechanical, electrical, optical, and microfluidic properties.

Main Results:

• The HG-TDP successfully enabled the co-fabrication of diverse hydrogel components into a single, compact fiber.
• The resulting all-hydrogel neural interfaces exhibited tissue-like mechanical compliance, minimizing gliosis.
• Integrated functionalities included an optical waveguide, conductive electrode, and microfluidic channel, enabling multimodal neural interfacing.
• High-quality neural signal recording, optogenetic stimulation, and chemical modulation were demonstrated.

Conclusions:

• The HG-TDP provides a scalable method for fabricating compact, fully hydrogel-based neural interfaces.
• These interfaces possess anti-fibrotic properties and integrated multimodal functionalities for advanced neural applications.
• This technology paves the way for next-generation neural devices with enhanced biocompatibility and performance.