Researchers at MIT have developed a microfluidic sensor that can detect levels of IL-6, a biomarker of sepsis, in tiny volumes of blood within just 25 minutes. The device could be an inexpensive alternative to existing point-of-care systems for sepsis detection.
Sepsis kills an estimated 250,000 patients in US hospitals every year. Detecting and diagnosing sepsis quickly is important for providing effective care in a timely manner. In recent years, numerous protein biomarkers for sepsis have been identified in the blood. Levels of one such protein, interleukin 6 (IL-6), begin to increase in the blood hours before any other sepsis symptoms begin to show, making it a promising early warning system. However, traditional lab assays struggle to detect IL-6 at these concentrations.
“For an acute disease, such as sepsis, which progresses very rapidly and can be life-threatening, it’s helpful to have a system that rapidly measures these nonabundant biomarkers,” said Dan Wu, a researcher involved in the study. “You can also frequently monitor the disease as it progresses.”
Indeed, traditional assays to detect sepsis biomarkers often require expensive, bulky machines. These make sepsis detection outside of a hospital setting impossible. To address this, a variety of point-of-care devices have been developed in recent years. However, these are frequently very expensive as they typically rely on costly optical components.
In an effort to create a less expensive alternative, these MIT researchers looked to miniaturize a magnetic bead-based assay. Their device contains a microfluidic channel that is loaded with a blood sample and microbeads that contain antibodies designed to capture IL-6. A peristaltic pump moves the liquid around the device, before the beads that are bound to IL-6 attach to an electrode. By passing a current through the electrode, the device can measure the amount of bound IL-6 on the beads, from which it can calculate the amount in the blood.
The device needs just 5 microliters of blood to test IL-6 levels, is simple to use, and has the potential to measure multiple biomarkers. “On their end, doctors just load in a blood sample using a pipette. Then, they press a button and 25 minutes later they know the IL-6 concentration,” said Wu. “This is very general platform. If you want to increase the device’s physical footprint, you can scale up and design more channels to detect as many biomarkers as you want.”
The research is due to be presented at the Engineering in Medicine and Biology Conference in Berlin.