A novel chitosan and polydopamine interlinked bioactive coating for metallic biomaterials

Area of Science:

• Biomaterials Science
• Surface Engineering
• Medical Device Coatings

Background:

• Chitosan coatings offer beneficial bioactive properties like antibacterial and antiplatelet effects for blood-contacted materials.
• Intravascular metal stents face challenges with structural integrity due to mechanical stress and potential substrate degradation.
• Adhesion strength between coating and substrate is critical for maintaining stent structural integrity.

Purpose of the Study:

• To enhance the adhesion strength and structural integrity of chitosan coatings on metallic substrates for biomedical applications.
• To investigate the use of polydopamine (PDA) as an intermediate layer and glutaraldehyde as a linking agent for improved coating adhesion.

Main Methods:

• Developed a novel coating system utilizing a polydopamine (PDA) intermediate layer and glutaraldehyde as a cross-linking agent.
• Applied this system to chitosan polymer coatings on metallic substrates.
• Evaluated coating adhesion strength compared to PDA-only and glutaraldehyde-linked silane layers, and bare metal.

Main Results:

• The novel chitosan film on the glutaraldehyde-linked PDA interface demonstrated a significant increase in adhesion strength.
• The coating's performance was comparable to bare Ni-free stainless steel, indicating good biocompatibility and substrate interaction.
• The developed interface successfully linked the chitosan polymer to the intermediate PDA layer.

Conclusions:

• A novel, robust chitosan coating system was successfully developed for metallic substrates.
• The glutaraldehyde-linked PDA interface significantly enhances chitosan coating adhesion, crucial for medical device integrity.
• This coating technology holds promise for applications requiring combined bioactive and anticorrosive properties, such as intravascular stents.