Team:Brasil-SP/TheIssue/OurSolution

     Several studies support Cystatin C as the best biomarker of renal dysfunction when compared to classical biomarkers (urea nitrogen and serum creatinine), because Cystatin C is very sensitive to changes in GFR (SHLIPAK and DAY, 2013). However, the available methods to evaluate the levels of Cystatin C are often very expensive and inefficient, such as the immunofluorescence method (SHLIPAK and DAY, 2013). Our solution to this problem is to develop a genetic circuit to detect different levels of Cystatin C in the blood. When the detectable levels of Cystatin C are higher than the normal, it will lead us to diagnose CKD and other renal dysfunctions in early stages. The genetic circuit is shown in the Figure below and the input information is based on Cystatin C inhibitory activity against cysteine proteases, in this case, cathepsin S.

     Another factor that delays early diagnosis the low accessibility of the test and the lack of methods to perform a more practical, fast and easy exam. With that in mind, we developed a microfluidic device with capable of storaging our Bacillus subtilis spores. The device will include different chambers containing: a spore activation media, standardized cathepsin S solution, clean up solution, and blood input site. All the chambers will be covered with a flexible membrane so pressure can be applied with the user's fingertip. We ultimately envision our device to be portable and electricity independent.

Reference

SHLIPAK MG, DAY, EC. Biomarkers for incident CKD: a new framework for interpreting the literature. Nature Review on Nephrology, 2013, 9(8):478-83. doi: 10.1038/nrneph.2013.108.