Small, sensitive biosensors could help doctors deliver personalized care, even in developing countries.
A portable biosensor that could show how disease is progressing in patients with Alzheimer’s could greatly improve people’s quality of life in the future, according to a new review published in Biosensors and Bioelectronics.
An FIU team led by Ajeet Kaushik, assistant professor of immunology at the Herbert Wertheim College of Medicine (HWCOM), is taking a new approach to diagnosing the disease: measuring the amount of a peptide called beta-amyloid in the blood with a cheap, quick, accurate point-of-care test. They hope their new approach will help patients, including those in developing countries, benefit from personalized treatment for Alzheimer’s disease.
Alzheimer’s is caused by high levels of beta-amyloid in the brain, which leads to the degeneration of brain cells. Doctors can use various types of scans and immunoassays–procedures for detecting or measuring substances based on their ability to act as antigens or antibodies–such as MRI (magnetic resonance imaging) and ELISA (enzyme-linked immunosorbent assay) to estimate the amount of beta-amyloid in the brain, giving them an indication of how the disease is progressing. But the protein can also be found in lower levels in blood, making it a useful biomarker to diagnose and monitor disease progression.
The team, from HWCOM’s Center for Personalized Nanomedicine at the Institute of NeuroImmune Pharmacology, included Institute Director and Distinguished Professor Madhavan Nair, and investigators Rahul Dev Jayant and Sneham Tuwari. Their research is supported by grants from the National Institutes for Health (NIH).
“This approach will really help President Obama’s BRAIN Initiative launched by NIH in 2013 to accelerate the development of new and innovative neurotechnologies and tools to understand the complex and progressive stages of various brain diseases including Alzheimer’s,” says Nair who serves on the BRAIN grant review panel.
Currently there is no sensitive or inexpensive way to measure beta-amyloid levels in the blood. The team behind the new review plans to change that.
“We want to develop a point of care system, where a small drop of blood plasma can reveal their beta-amyloid level immediately so that a doctor can tailor a patient’s therapy immediately,” explains Kaushik, lead author of the review. “The drugs used to treat Alzheimer’s disease can have side effects, so it’s better for patients not to overdose. With the right data, doctors can respond quickly to changes in a patient’s brain by reducing or increasing their dose.”
In the review, the team looked at each of the methods available to measure beta-amyloid concentration in brain tissue and in blood. None of the existing tests can be done at the bedside and all need special and large samples. They also take a long time to generate a useful result – the main existing test, called ELISA, takes six to eight hours. In comparison, the cheap, simple biosensor Kaushik and colleagues describe can measure beta-amyloid in the blood at tiny concentrations in just half an hour.
To develop the new biosensor the team will need lots of bio-fluid samples taken at different stages of the disease. Finding all the samples they need will be challenging, but Kaushik says the review demonstrates a biosensor is achievable in the future, and he hopes it will help scientists study disease progression and help clinicians deliver personalized therapy to patients.
Written by Robyn Nissim and Ileana Varela