Back
In the field of hemodialysis, the selection between high flux and low flux dialysis membranes carries significant patient implications. Employing different methods and techniques, we examined the hospital use of polyarylethersulfone (PEAS) low and high flux dialyzers. We utilized advanced synchrotron imaging technology at the Canadian Light Source, in conjunction with clinical analyses and Energy-Dispersive X-ray Spectroscopy (EDX) techniques. This study aims to determine which membrane would potentially offer fewer side effects for the patient.
In this study, we utilized radiation micro-computed tomography (SR-µCT) imaging at the Canadian Light Source (CLS) to visualize pore size distribution and human serum protein deposition and attachment across the membrane thickness in real-time. This imaging procedure employed a beam monitor AA-40 coupled with a high-resolution camera (PCO Dimax HS) featuring a field of view (FOV) measuring 4.4 × 2.2 mm and individual pixels of 5.5 μm. Platelet factor levels in patients' blood were quantified using the Human CXCL4/PF4 Quantikine ELISA Kit (CAT #DPF40), and quantification was performed using a microplate reader. Blood samples collected from patients were incubated with both high flux and low flux membranes for 1 hour. To assess the membranes' surface morphology and confirm their elemental composition similarity, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) were employed, utilizing the SU8010 by Hitachi High-Tech and the Ultim Max 170 by Oxford Instruments, respectively.
The increased absorption of human serum albumin protein leads to protein depletion in patients, progressive membrane clogging, and heightened risks of blood activation and inflammation. High-flux membranes absorb more albumin than low-flux membranes, attributed to larger pore sizes. Over time, protein absorption decreases, likely due to membrane pressure-induced leakage. PF4 concentration is higher with increased clotting, with levels measuring 414.63 ng/ml for low-flux and 381.27 ng/ml for high-flux membranes. Lower platelet activation with high-flux membranes is due to reduced material exposure. BET analysis reveals total pore volumes of 0.086 m3/g for high-flux and 0.071 m3/g for low-flux membranes, while surface roughness differs between them. SEM-EDX shows similar sulfur and nitrogen levels in both membranes, suggesting equivalent chemical composition.
In summary, the high flux membranes' enhanced protein absorption, attributed to their wider pore sizes, raises concerns, including increased protein leakage. Conversely, low flux membranes demonstrated a disadvantage by exhibiting higher platelet activation, indicating a heightened risk of blood clotting due to surface characteristics. These findings underscore the critical importance of selecting membranes tailored to specific dialysis requirements, accounting for factors such as protein absorption, clotting risks, and overall dialysis efficiency. Further research is imperative to discern the clinical implications of these insights and to optimize membrane selection in hemodialysis applications.