Polysaccharide Layer-by-Layer Coating for Polyimide-Based Neural Interfaces

Area of Science:

• Biomaterials Science
• Neuroscience Engineering
• Medical Device Technology

Background:

• Implantable flexible neural interfaces (IfNIs) offer direct neural signal modulation but face challenges with long-term biocompatibility due to foreign body reactions.
• These reactions can degrade electrical performance and cause tissue damage, limiting the clinical utility of IfNIs.

Purpose of the Study:

• To fabricate and characterize a biocompatible nanostructured thin film coating for polyimide (PI)-based IfNIs.
• To evaluate the effectiveness of layer-by-layer (LbL) deposition techniques in enhancing IfNI surface properties and long-term integration.

Main Methods:

• Fabrication of a polysaccharide nanostructured thin film using the layer-by-layer (LbL) technique on polyimide (PI) substrates.
• Comparison of dip coating and spin coating methods for LbL deposition.
• Morphological and physiochemical characterization of the coated surfaces.

Main Results:

• Both dip and spin coating successfully produced smooth, nanostructured thin film coatings on PI surfaces.
• The nanostructured coatings significantly enhanced surface hydrophilicity compared to bare PI.
• Spin coating provided superior control over coating properties, allowing for tunable physiochemical and morphological characteristics.

Conclusions:

• The proposed polysaccharide nanostructured film is a biocompatible coating for IfNIs.
• This coating strategy, particularly with spin coating, can improve tissue/electrode integration and enhance the long-term biocompatibility of neural interfaces.