Biocompatible benzocyclobutene (BCB)-based neural implants with micro-fluidic channel

Area of Science:

• Biomaterials Engineering
• Neuroscience
• Medical Devices

Background:

• Chronic neural implants require biocompatible, flexible materials for long-term use.
• Delivering therapeutics directly to neural tissue is challenging.
• Poly-benzocyclobutene (BCB) offers promising properties for neural applications.

Purpose of the Study:

• To fabricate and evaluate a novel poly-benzocyclobutene (BCB)-based intracortical neural implant.
• To integrate micro-fluidic channels for targeted drug delivery.
• To assess the implant's biocompatibility, mechanical robustness, and neural recording capabilities.

Main Methods:

• Fabrication of a single-shank BCB implant with integrated micro-fluidic channels and recording sites.
• In vitro cytotoxicity testing on cultured cells.
• Mechanical testing to evaluate penetration robustness in rat pia.
• Impedance measurements at 1 kHz.
• In vivo neural signal recording from rat barrel cortex.

Main Results:

• The BCB implant demonstrated flexibility, biocompatibility, and chemical inertness.
• In vitro tests showed no adverse toxic effects.
• The implant, reinforced with a silicon backbone, successfully penetrated the rat pia without buckling.
• Average impedance at 1 kHz was 1.2 MΩ.
• Simultaneous neural signal recordings were successfully achieved in vivo.

Conclusions:

• BCB-based neural implants with embedded micro-fluidic channels are feasible for chronic applications.
• The fabricated implant exhibits suitable properties for neural interfacing and drug delivery.
• The device demonstrates potential for simultaneous neural recording and therapeutic delivery in the brain.