Ex vivo interactions and surface property relationships of polyetherurethanes

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Medical Device Materials

Background:

• Polyurethanes are widely used in blood-contacting medical devices.
• Understanding polyurethane thrombogenesis is crucial for device safety.
• Limited data exists on how specific polyurethane components affect blood clotting.

Purpose of the Study:

• To investigate blood-polyurethane interactions.
• To determine the influence of polyurethane composition on thrombogenesis.
• To correlate surface properties with blood-material responses.

Main Methods:

• Acute canine ex vivo series shunt experiments.
• Multiprobe surface characterization: contact angle, ESCA, ATR-IR, SEM.
• Evaluation of polyurethanes with varied soft/hard segments, solvents, and commercial samples.

Main Results:

• Surface concentration and type of hard segment significantly impact blood response.
• Hard segment concentration's effect varies with copolymer composition.
• Casting solvents alter surface properties and thrombogenicity.
• Methanol extraction improved thromboresistance of commercial polyurethanes.

Conclusions:

• Polyurethane surface composition, particularly hard segment characteristics, is critical for blood compatibility.
• Fabrication conditions, such as solvent choice, must be optimized.
• Methanol extraction offers a method to enhance the hemocompatibility of existing polyurethanes.