Simple bio‐inspired coating of ureteral stent for protein and bacterial fouling and calcium encrustation control

Abstract

Encrustation, caused by deposition of calcium and magnesium salts present in urine, is a common problem of indwelling urinary devices, such as ureteral stent. Encrustation was also found to be related to urinary tract infections; thus, it is necessary to prepare ureteral stents with antibacterial and antifouling surfaces to mitigate the occurrence of encrustation. In this study, commercial ureteral stent was coated with polydopamine (PDA), formed from self‐polymerization of dopamine. The PDA coating was optimized in terms of dopamine concentration, pH, and coating time using response surface methodology. The chosen response parameters for optimization were calcium oxalate (CaC2O4) encrustation and protein adsorption. Optimized PDA coating conditions were determined to be the following: pH 9.0, 2 mg/mL DA, and 3 days coating. The optimized PDA‐coated ureteral stent exhibited outstanding resistance against CaC2O4 encrustation, protein fouling, and bacterial adhesion due to its hydrophilic and functional coating layer. In comparison with the pristine ureteral stent, PDA coating was able to suppress approximately 97% and 87% of CaC2O4 and protein adsorption, respectively. The PDA‐coated ureteral stent was compared against those of commercially available ureteral stents and found to have superior encrustation and protein fouling mitigation performance. Finally, PDA coating was found to be highly stable for a storage period of 90 days, whether stored in wet or dry conditions.

Establishment of an artificial urine model in vitro and rat or pig model in vivo to evaluate urinary crystal adherence

“…The stents were first placed in 1 mL 8% HNO 3 and placed in ultrasonication bath to dissolve the crystals. The solution was afterwards diluted using 1% HNO 3 (aq) prior to ICP-OES analysis 13 . The surface morphology and elemental mapping of the stents were characterized using a scanning electron microscope (SEM, Phenom ProX, Thermo Fisher Scientific, Japan) and SEM-coupled with energy dispersive spectroscopy (SEM–EDS) analysis.…”