Blood compatibility of surfaces modified by plasma polymerization

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Cardiovascular Research

Background:

• Blood-contacting polymeric materials are crucial for medical devices like vascular grafts.
• Thrombosis, or blood clot formation, remains a significant challenge, leading to device failure.
• Understanding blood-material interactions is key to developing safer and more effective biomedical implants.

Purpose of the Study:

• To evaluate the thrombogenicity of plasma-polymerized materials in a baboon model.
• To assess the impact of surface modification on acute and chronic arterial thrombosis.
• To investigate the role of surface chemistry and texture in blood-material interactions.

Main Methods:

• Plasma polymerization was used to modify tubular polymeric materials.
• Electron spectroscopy for chemical analysis (ESCA) determined polymer surface composition.
• Arteriovenous shunts in baboons were used to assess steady-state thromboembolism and acute thrombus formation.
• 111In-platelet survival measurements and scintillation camera imaging quantified platelet consumption and deposition.

Main Results:

• Nine plasma polymers on silicone rubber showed low platelet consumption, near the detection limit, indicating relative nonthrombogenicity.
• Standard expanded polytetrafluoroethylene (ePTFE) vascular grafts induced significant platelet deposition.
• Modification of ePTFE grafts with a hexafluoroethane/H2 plasma polymer reduced platelet deposition by 87% (p < 0.001) without altering surface morphology.

Conclusions:

• Both surface chemistry and texture of prosthetic materials significantly influence thrombogenesis.
• Plasma polymerization is a valuable method for independently assessing these variables.
• This technique holds potential for minimizing adverse blood-material interactions in biomedical devices.