Abstract: TH-PO0868
Bacterial Inhibition and Urea Removal in a TiO2-Catalyzed Dialysis Regeneration Prototype
Session Information
- Dialysis: Prescription, Physiology, and Treatment Optimization
October 22, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Dialysis
- 801 Dialysis: Hemodialysis and Frequent Dialysis
Authors
- Chen, Louis N., University of Washington, Seattle, Washington, United States
- Himmelfarb, Jonathan, Icahn School of Medicine at Mount Sinai, New York, New York, United States
- Ratner, Buddy, University of Washington, Seattle, Washington, United States
Background
The University of Washington has developed a platform comprising several TiO2 photooxidation cells to remove urea from spent dialysate. Here, we quantify the effectiveness of a single photooxidation cell in inhibiting the growth of suspended bacteria and decomposing urea.
Methods
We applied a clinically isolated pathogen, Staphylococcus aureus, at an initial suspended concentration of 107 colony-forming units/mL (CFU/mL), of a mock dialysate solution (10mM urea, 0.9% NaCl) that was recycled through a single TiO2 photooxidation cell for 8 hours (n=3). As a negative control, bacterial suspensions were recycled through the system without the photooxidation cell operating. Suspended bacterial and urea concentrations were periodically determined using colony-forming units (CFU) and urea nitrogen (BUN) colorimetric detection, respectively.
Results
To assess bacterial growth and urea measurement, 1 mL of a bacterial-urea-saline solution was periodically sampled from the recycle fluid then analyzed. Exposed to TiO2 only, pathogen concentrations remained stable at approximately 107 CFU/mL over 8 hours. However, exposure to UV-TiO2 photocatalysis, in the presence of a bicarbonate-buffered solution or not, resulted in a 99.9% reduction in viable bacterial counts within 2 hours. In contrast, the urea concentration remained unchanged at 35 mg/dL after 8 hours of circulation. With UV illumination, urea concentration decreased to 66% and 44% in bicarbonate buffer. An additional control group of Staphylococcus aureus suspended in saline solution showed stable bacterial counts, with no detectable urea released into the solution.
Conclusion
The TiO2-based photooxidation system effectively inactivates planktonic pathogenic bacteria while removing urea from a dialysate-mimicking solution, demonstrating dual functionality in a portable dialysis prototype.