Researchers from Florida Atlantic University’s College of Engineering and Computer Science have developed a fast and reliable new method to continuously monitor sickle cell disease using a microfluidics-based electrical impedance sensor.

Results of the study, published in the American Chemical Society’s journal ACS Sensors, indicate that such innovative technology can characterize the dynamic cell sickling and unsickling processes in sickle blood without microscopic imaging or biochemical markers.

Sickle cell anemia explained

Sickle cell disease is a group of inherited red blood cells disorders. People who have sickle cell disease have an abnormal protein in their red blood cells. Most individuals who suffer from sickle cell disease are of African ancestry, but the condition is also common in people with a Hispanic background. The disease runs in families and couples planning to have children can have genetic testing if they think their offspring will be at risk. Sickle cell is a life-long illness; the severity of the disease varies widely from one person to another.

“Sickle cell anemia — causes, symptoms, diagnosis, treatment & pathology” by Osmosis, YouTube.

Early symptoms of sickle cell disease include swelling of the hands and feet; symptoms of anemia, including fatigue, or extreme tiredness; and jaundice. As time goes by, sickle cell can lead to complications such as infections, delayed growth, and episodes of pain (often called pain crises). Most children who have sickle cell disease are pain-free between crises, yet teenagers and adults may also suffer with chronic, regular pain. In the course of a lifetime, the disease can affect a patient’s spleen, brain, eyes, lungs, liver, heart, kidneys, genitals, joints, bones and skin.

Prodigy of Mobb Deep speaks to a young teenager about his sickle cell condition. The musician has since passed away from complications of the disease. YouTube.

A blood and bone marrow transplant is currently the only cure for sickle cell disease, and only a limited number of people who have the condition are able to have the transplant. There are a few effective treatments that can reduce symptoms and extend life expectancy. Early diagnosis and regular medical care to prevent complications can lead to an improved quality of life.

An easier way to monitor sickle cell

Managing sickle cell disease demands that clinicians are aware of the ongoing sickling behavior in patient red blood cells. In an ideal world, such changes would be detected before cell damage and serious symptoms develop, yet current optical microscopy techniques to monitor the disease are time consuming and cannot provide clinicians with frequent, real-time updates on cell behavior.

This problem inspired the Florida Atlantic University researchers to develop a more convenient methodology to monitor sickle cell disease. Their solution consists of a microfluidic chip that uses impedance measurements to assess red blood cell behavior. The chip comes with a patient blood sample and the sample is exposed to conditions of high and low oxygen, which can stimulate the cells to sickle and unsickle. Electrical impedance detection measures the rate of sickling and unsickling. Such can tell clinicians about the potential of the cells to contribute to blood vessel blockage as well as abnormal blood flow.

This video shows the response of sickle cells subjected to cycles of oxygenation and deoxygenation, observed under a microscope. The top right inset shows a representative signal from the microfluidic impedance sensor, which is shown in the lower right corner. The sensor generates the signal (quantitative and real-time) as shown by the curve in the inset and offers capacity for microscopic observation of cell conditions. Florida Atlantic University, YouTube.

The researchers were able to correlate the measurements they made utilizing the new microfluidic device with important patient hematological parameters, and the technique might provide clinicians with information on disease severity, the risk of blood vessel blockage, and if a specific treatment is working or not.

“The combination of electrical impedance measurement and on-chip hypoxia control provides a promising method for rapid assessment of the dynamic processes of cell sickling and unsickling in patients with sickle cell disease,” stated Sarah E. Du, a researcher involved in the study. “In addition, electrical impedance measurement is naturally quantitative, real-time, and offers a convenience in direct or indirect contact with the samples of interest, allowing integrations to microfluidics platform and optical microscopy.” she added.