Biocompatible two-layer tantalum/titania-polymer hybrid coating

Area of Science:

• Biomaterials Science
• Materials Engineering
• Nanotechnology

Background:

• Developing radiopaque and biocompatible coatings is crucial for advanced medical devices.
• Tantalum coatings offer X-ray visibility but suffer from poor adhesion and susceptibility to damage.
• Existing protective layers often lack the necessary flexibility and biocompatibility.

Purpose of the Study:

• To create a novel two-step coating procedure for radiopaque and biocompatible applications.
• To evaluate the adhesion, durability, and biocompatibility of organic-inorganic hybrid coatings over tantalum layers.
• To identify a suitable protective coating for flexible medical devices utilizing radiopaque markers.

Main Methods:

• A sputtering technique was used to deposit a tantalum layer onto plastic substrates.
• Organic-inorganic hybrid coatings using poly-ε-caprolactone (PCL) or carboxy-terminated polydimethylsiloxane (PDMS) were synthesized via sol-gel.
• Cytotoxicity tests with vascular wall resident-mesenchymal stem cells (VW-MSCs) assessed biocompatibility.
• Scanning Electron Microscopy (SEM) evaluated coating integrity under substrate deformation.

Main Results:

• Tantalum layers provided adjustable X-ray visibility but exhibited poor adhesion.
• Both PCL- and PDMS-based hybrid coatings demonstrated excellent adhesion and biocompatibility.
• SEM analysis revealed cracking in the PCL-hybrid under deformation, while the PDMS-hybrid remained intact.
• The PDMS-based hybrid coating proved to be a robust protective layer for the tantalum marker.

Conclusions:

• The developed two-step coating procedure successfully created radiopaque and biocompatible layers.
• The PDMS-based organic-inorganic hybrid coating offers superior mechanical stability and crack resistance compared to PCL-based coatings.
• This PDMS-hybrid coating is a promising candidate for protecting sputtered tantalum radiopaque markers in flexible medical devices.