Transport of Nitric Oxide (NO) in Various Biomedical grade Polyurethanes: Measurements and Modeling Impact on NO Release Properties of Medical Devices

Nitric oxide (NO) releasing polymers are promising in improving the biocompatibility of medical devices. Polyurethanes are commonly used to prepare/fabricate many devices (e.g., catheters); however, the transport properties of NO within different polyurethanes are less studied, creating a gap in the rational design of new NO releasing devices involving polyurethane materials. Herein, we study the diffusion and partitioning of NO in different biomedical polyurethanes via the time-lag method. The diffusion of NO is positively correlated with the PDMS content within the polyurethanes, which can be rationalized by effective media theory considering various microphase morphologies. Using catheters as a model device, the effect of these transport properties on the NO release profiles and the distribution around an asymmetric dual lumen catheter are simulated using finite element analysis and validated experimentally. This method can be readily applied in studying other NO release medical devices with different configurations.