Fatigue and hemocompatibility of polymer materials

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Biomedical Engineering

Background:

• Hemocompatibility and fatigue life are crucial for artificial hearts and circulatory assist devices.
• Synthetic polymers are essential biomaterials for these applications, requiring rigorous testing.

Purpose of the Study:

• To compare hemocompatibility and fatigue behavior of three segmented polyurethanes (PUs) against a Czech PU and organosilicone rubber (RKM).
• To investigate the relationship between polymer type, structural changes under cyclic loading, and hemocompatibility.

Main Methods:

• Uniaxial and biaxial static strain tests were performed.
• Accelerated fatigue tests predicted in vivo performance.
• Fatigue damage assessed using light transmission/scattering, platelet adhesion, and morphological changes.

Main Results:

• Segmented polyurethanes exhibited superior elasticity compared to RKM, which required reinforcement.
• Czech PU demonstrated excellent mechanical properties, including high elasticity and low creep.
• Cyclic loading caused insignificant changes in cell morphology but increased platelet adhesion across all tested materials.

Conclusions:

• The study highlights the mechanical and hemocompatibility trade-offs in synthetic polymers for cardiovascular devices.
• Increased platelet adhesion post-fatigue is a critical factor to address for improved hemocompatibility in artificial hearts and assist devices.