# Performance characterization and biocompatibility assessment of silicone polyurethanes for polymer heart valve applications

## TL;DR

This study evaluates four silicone polyurethane materials for heart valves, finding that higher silicon content improves biocompatibility but reduces mechanical strength.

## Contribution

The study provides a detailed performance and biocompatibility comparison of four silicone polyurethanes for heart valve applications.

## Key findings

- Higher silicon content improves biocompatibility by forming a protective layer that reduces cell and protein adsorption.
- Increased silicon content leads to decreased mechanical performance, risking mechanical failure in heart valves.
- Surface silicon migration enhances biological stability but compromises mechanical strength.

## Abstract

Silicone polyurethanes have gained widespread application in the biomedical field due to their excellent biocompatibility. This study comprehensively investigates four silicone polyurethane materials suitable for polymer heart valves, each exhibiting distinct chemical compositions and structural characteristics, leading to significant differences, particularly in mechanical performance and biocompatibility. Surface analysis reveals an elevated surface silicon element content in all materials compared to the bulk, indicating a migration of silicon elements towards the surface, providing a structural basis for enhancing biological stability and biocompatibility. However, higher silicon content leads to a decrease in mechanical performance, potentially resulting in mechanical failure and rupture in artificial heart valves. Concerning biocompatibility, an increase in silicone content diminishes the material's adsorption capability for cells and proteins, consequently improving its biocompatibility and biological stability. In summary, while high silicone content leads to a reduction in mechanical performance, the formation of a “silicon protective layer” on the material surface mitigates cell and protein adsorption, thereby enhancing biocompatibility and biological stability. Through comprehensive testing of the four silicone polyurethane materials, this study aims to provide insightful perspectives and methods for selecting materials suitable for polymer heart valves. Additionally, the thorough performance exploration of these materials serves as a crucial reference for the performance assessment and biocompatibility research of polymeric artificial heart valve materials.

Silicone polyurethanes have gained widespread application in the biomedical field due to their excellent biocompatibility.