Cells and Materials


Deposition of infection-induced stone material on urinary catheters is a common problem in urological patients. Therefore, a crystallization model was developed in order to form this material in a reproducible manner. Furthermore, the dissolving potency of two solutions (Suby-G® and Solution-R®) was investigated with this model. The encrustations were examined by infrared (IR) spectroscopy, chemical encrustation analysis , scanning electron microscopy (SEM) and X-ray microanalysis. In addition, the encrustations were calculated from the results of the urine analysis, before and after each experiment, as contents remaining in each artificial bladder. The model conditions changed during the experiment and led to supersaturation for struvite. The encrustation analysis resulted in 73 .5 % (IR spectroscopy) and 78.5 % struvite (chemical encrustation analysis) respectively. The calculated encrustation by urinary losses of stone forming contents resulted in 79.3% struvite. SEM showed that after the experiment, the catheters carried large amounts of mineral deposition and bacterial biofilm on their inner and outer surface. During the experiment, the catheters lost their homogeneous surface; cracks appeared and material was lost. X-ray microanalysis showed peaks for Mg, P and Ca (infection-induced stone material), Si (catheter material), Al (sample carrier) and Ag (conductive material) and supported the encrustation analysis. The solutions tested showed high dissolving capacities for infection stone material. After irrigation of the bladder with both solutions tested, 70 % and 85 % respectively, of struvite was dissolved.