Accurate prediction of pore size distribution in hemodialysis membranes based on gel permeation chromatography

Abstract

ABSTRACT Dialyzers play an important role in hemodialysis, a process used for the treatment of chronic kidney disease. The pore size distribution (PSD) is one of the key factors affecting the performance of the dialyzer. However, due to the inherent characteristics of the current method of testing PSD, the accuracy of the test results needs to be improved. We improved the dextran retention method by considering concentration polarization and backfiltration, and explored the experimental conditions to obtain a more accurate PSD. Moreover, the experimental data obtained via gel permeation chromatography were further processed to represent the relationship more intuitively between pore size and pore size probability density. The in vitro toxin removal of the dialyzers was used to further analyze the relationship between the PSD and dialyzer performance. The results showed that the increase in the pore size of the hollow fiber membrane had no obvious effect on the clearance of small molecule toxins. However, under certain conditions, a larger pore size increased the clearance of the dialyzers on medium molecules. More accurate PSD results can help manufacturers analyze the clearance performance of dialyzers. Consequently, specific dialyzers can be designed for different situations, resulting in more effective treatment of the patients.