Real-Time Monitoring of Urinary Encrustation Using a Quartz Crystal Microbalance

Encrustation
on the surface of urological devices such as ureteral
stents leads to their blockage. However, limited tools are available
for fast and real-time monitoring and modeling of the encrustation
process. In this work, we have developed a model for in vitro study of encrustation and coupled it to an online monitoring QCM
technique. The QCM biosensor is precoated with a polymer that is representative
of the surface of a ureteral stent and subsequently coated with urease
to facilitate crystallization of calcium and magnesium phosphate.
The changes in deposition of crystals on the polymer surface are monitored
quantitatively using a quartz crystal microbalance (QCM) biosensor.
The QCM sensor is capable of dynamic, label-free detection and has
a very high sensitivity. Experimental data generated using this model
shows that pretreatment of the sensor surface with urease significantly
induces early stage encrustation as compared to the untreated sensor
surface, which emulates the real encrustation process. This encrustation
study model has a high utility in screening studies for materials
used in urological devices.