Multiplexed AKI biomarker detection with a single molecule biosensor

The key objective of this programme of work is to improve the clinical outcomes for patients affected by Acute Kidney Injure (AKI). AKI is a silent killer, which occurs in acutely ill patients and is associated with poor outcomes, which include increased length of hospital stays, increased mortality, and long-term adverse outcomes including chronic kidney disease and cardiovascular mortality. Multiple reports have also described the association of AKI with COVID-19. A recent publication identified that 36.6% of patients admitted to hospital with COVID-19 developed AKI, with 14.3% requiring dialysis and 35% of patients dying. AKI occurs early and in temporal association with respiratory failure. In the UK, during the first wave of the COVID-19 pandemic, the provision of dialysis to patients on the ICUs was pushed to the limit.

Our proposed solution is a radically new diagnostics device able to detect two biomarkers linked to AKI, C-reactive protein (CRP) and Neutrophil Gelatinase Lipocalin (NGAL). These biomarkers can rise by more than 100-fold within a matter of hours in response to changes in an individual's AKI disease state, making them very important candidates for early diagnosis of AKI.

The device employs nanopore technology to detect the presence of these biomarkers in biological fluids within minutes using a hand-held device. Nanopore technology allows the counting of biomarkers one at the time as it is sensitive to just a single molecule passing through the nanopore which is a key advantage over competing technologies that often require the detection of trillions of analytes before a signal can be processed.

The detection of biomarkers using nanopore technology is still challenging because the technology provides the same signal regardless of the biomarker analysed which is a particular problem when the test is carried out in biological fluids like blood.

This project is based on our recent discovery that allowed to fingerprint the signal of individual biomarkers while enhancing the performance of the test in biological fluids such as blood. Our discovery employed DNA origami as carriers able to bind the biomarker of interest and improve its detection with the nanopore platform. DNA origami is a technique that allows to fold long DNA molecules into a robust geometry of choice, similar to the Japanese art of paper origami. We have designed DNA origami shaped like a picture frame able to capture AKI biomarkers (CRP) inside the void. This particular design generates a unique nanopore signal allowing us to count how many biomarkers were captured per DNA origami. This approach allowed us to measure the concentration of biomarkers in biological fluids in a matter of minutes.

Within this programme of work we will further refine this technology to allow the simultaneous detection of two biomarkers important for the early diagnosis of AKI (CRP and NGAL). We will also expand the range of biomarkers that can be analysed with our technology so that it could be use to tackle other diseases in the future. We will have partnered with a leading instrument manufacturer to deliver a prototype instrument that will be tested in clinical settings in collaboration with NHS experts. Alongside the technology development work, we will also demonstrate the clinical relevance of this novel and highly innovative approach by defining a clinical use case for the technology to facilitate the early detection of AKI. In parallel, we will develop an early economic model to demonstrate the clinical and economic consequences of our proposed diagnostic device.