A novel polymer for potential use in a trileaflet heart valve

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Cardiovascular Engineering

Background:

• Novel polyolefins are being explored for cardiovascular applications due to their inherent stability.
• Poly(styrene-b-isobutylene-b-styrene) (Quatromer) exhibits oxidative stability, suggesting potential for heart valve prostheses.

Purpose of the Study:

• To evaluate the hemocompatibility and mechanical durability of Quatromer for trileaflet heart valve applications.
• To compare Quatromer's performance against approved polyurethane (PUR) and native valve tissue.

Main Methods:

• Mechanical characterization using static tensile and dynamic fatigue tests (tension-tension, bending).
• Comparison of isotropic and polypropylene (PP) fiber-reinforced Quatromer with PUR.
• Hemocompatibility assessment via platelet deposition studies using radiolabeled platelets in a parallel plate flow chamber.

Main Results:

• PP fiber reinforcement significantly improved Quatromer's tensile and fatigue properties, matching or exceeding PUR.
• Quatromer exhibited comparable platelet deposition to PUR, with significantly lower deposition than glutaraldehyde-fixed porcine valve material.
• No significant difference in thrombotic potential was observed between Quatromer and PUR.

Conclusions:

• Quatromer possesses suitable hemocompatibility and mechanical durability for polymer trileaflet heart valves.
• Fiber reinforcement is an effective strategy to tailor the mechanical performance of Quatromer for cardiovascular devices.