Surface roughness and edge geometries in hemolysis with rotating disk flow

Area of Science:

• Biomaterials Science
• Hemodynamics
• Medical Device Design

Background:

• Biocompatibility assessment is crucial for blood-contacting materials.
• Hemolysis, the rupture of red blood cells, is a key indicator of blood material interactions.
• Surface properties and device hydrodynamics influence hemolysis.

Purpose of the Study:

• To investigate the relationship between surface roughness and hemolysis in a rotating-disk device.
• To evaluate the impact of device geometry, specifically corners, on hemolysis.
• To compare hemolysis in different plastic materials and corner designs.

Main Methods:

• Utilized a rotating-disk device with polyethylene and polycarbonate disks.
• Tested various surface roughness levels, from under 4 microns to 65 microns.
• Compared hemolysis generated by square-cornered disks with corner-beveled designs.

Main Results:

• Hemolysis increased sharply for roughness above approximately 11 microns.
• Gross roughness (65 microns) resulted in different hemolysis kinetics but not necessarily more severe hemolysis.
• Corner geometry significantly contributed to hemolysis, with beveled edges generally increasing it compared to flat disks.

Conclusions:

• Surface roughness below 4 microns has a negligible effect on hemolysis.
• Device geometry, particularly sharp corners, is a critical factor in hemolysis, potentially masking material-specific effects.
• Careful consideration of device design is necessary to minimize material-induced hemolysis and accurately assess biocompatibility.