Abstract: FR-PO0512
Self-Sterilization for Portable TiO2-Catalyzed Dialysis Regeneration Systems
Session Information
- Dialysis: Hemodiafiltration, Ultrafiltration, Profiling, and Interdialytic Symptoms
November 07, 2025 | Location: Exhibit Hall, 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, University of Washington, Seattle, Washington, United States
- Ratner, Buddy, University of Washington, Seattle, Washington, United States
Background
The University of Washington has developed a TiO2 photooxidation platform to remove urea effectively. Here we quantify the effectiveness of a single photooxidation cell in inhibiting the growth of suspended bacteria and bacterial attachment.
Methods
We applied multiple clinically isolated pathogens with an initial concentration of 107 colony-forming units (CFU/mL), including E. coli, P. aeruginosa, S. aureus, and S. epidermidis, to a mock dialysate solution that was recycled through a TiO2 photooxidation cell for 1 and 4 hours (n=3). As a negative control, bacterial suspensions were recycled through a system without the photooxidation cell. Suspended bacterial concentrations and bacterial attachment on surfaces were periodically determined using quantification methods.
Results
To assess bacterial growth, 1 mL of a bacterial-urea-saline solution was analyzed. In the absence of treatment, all four pathogens maintained a concentration of approximately 107 CFU/mL over 1 hour. However, exposure to UV-TiO2 photocatalysis, including in a bicarbonate-buffered solution, resulted in a 99.9% reduction in viable bacterial counts. In a 4-hour experiment, bacterial growth in solution and attachment to the internal surfaces of polyvinyl chloride tubing were measured. In an untreated system, 107 CFU/mL of bacteria remained viable in solution, and 105 CFU/cm2 of bacteria adhered to surfaces. In contrast, both the standard and buffered photocatalysis treatments achieved near-zero bacterial viability by one hour for most species. A slight residual presence of 104 CFU/mL (99.9% decrease) was noted only for Staphylococcus epidermidis.
Conclusion
The TiO2-based photooxidation system effectively deactivates pathogenic bacteria from dialysate mimic solution and surfaces, demonstrating antimicrobial potential in a portable dialysis prototype.