Abstract: PO0922
Nanostructured Capillary Membranes for Size-Selective Hemofiltration
Session Information
- Leveraging Technology and Innovation to Predict Events and Improve Dialysis Delivery
November 04, 2021 | Location: On-Demand, Virtual Only
Abstract Time: 10:00 AM - 12:00 PM
Category: Dialysis
- 701 Dialysis: Hemodialysis and Frequent Dialysis
Authors
- Cheng, Peifu, Vanderbilt University, Nashville, Tennessee, United States
- Fornasiero, Francesco, Lawrence Livermore National Laboratory, Livermore, California, United States
- Ferrell, Nicholas J., Vanderbilt University, Nashville, Tennessee, United States
- Roy, Shuvo, University of California San Francisco, San Francisco, California, United States
- Fissell, William Henry, Vanderbilt University, Nashville, Tennessee, United States
- Kidambi, Piran, Vanderbilt University, Nashville, Tennessee, United States
Background
Size-selective separations offer potentially transformative advances for hemofiltration. In the context of hemodialysis, the tradeoff between selectivity and permeability often results in large package sizes and high driving pressures that limit wearable and implantable options of therapy. Here, we report on composite membranes with vertically aligned precise nanoscale capillaries with improved permeability.
Methods
Arrays of carbon nanotubes (CNTs) were synthesized via chemical vapor deposition and the catalyst composition was carefully selected to achieve a uniform distribution of diameters. The area between the CNTs were filled with a polymer to form a membrane. The CNT membranes were backed with microporous silicon supports and mounted into a filtration cell. Hydraulic permeability was calculated from gravimetric flow rates at stepped transmembrane pressures. Size-selectivity was measured by filtering fluorescently-labeled polydisperse Ficoll in phosphate-buffered saline. Size-specific Ficoll concentrations in feed and filtrate were measured by size-exclusion chromatography.
Results
CNT membranes membrane exhibited a cut-off ~6nm and the measured hydraulic permeability was 102.3 ml h-1 m-2 mmhg-1 compared to published data of 30 ml h-1 m-2 mmhg-1 for conventional high flux dialyzers. CNT membranes retained large molecules while passing small and medium-sized molecules. Sieving coefficient at 2 nm, approximately the size of b2 microglobulin, was unity (Figure).
Conclusion
The CNT membranes provide excellent middle molecule clearance and hydraulic permeability multiples of conventional membranes. Further research is necessary to move to clinically implement this technology.