APTITUDE: Novel Aptamer Technology for Measuring Interleukin at the bedside

Dr Susan Giorgi-Coll, University of Cambridge

There exists a need for a rapid, low-cost and easy-to-use point-of-care clinical test for diagnostic measurement of inflammation (e.g. injury or infection), by analysing patients’ body fluids, including blood plasma, cerebrospinal fluid (CSF) and brain fluid (microdialysates). The assay we aim to develop will have potential applicability in hospital wards, clinics, GP surgeries, care homes, and in patients’ own homes. The aim of the proposed project is to develop a proof-of-concept version of a novel bedside test for the detection of interleukin-6 (IL-6), an important inflammatory molecule. The proof-of-concept version will be a preliminary study for eventual application of this test for detection and monitoring human brain injury and infection, specifically traumatic brain injury (TBI) and bacterial meningitis in the first instance. IL-6 is a molecule produced by the immune system which plays a key role in a wide range of disease states. Increasing IL-6 can indicate development or advancement of an infection or injury through pathological inflammation. Early detection enabled by a bedside test can facilitate timely clinical intervention with great benefit to patients. Although this test is being developed with brain injury or infection in mind, due to the involvement of IL-6 in many different disease states, the bedside test will be applicable in a variety of clinical settings.The proposed test design uses aptamers, which are synthetic DNA strands designed to bind specifically to a target molecule, to bind IL-6. Aptamer-based tests offer significant advantages over the current state-of-the-art diagnostic tests in terms of sensitivity, reliability, cost, and easy storage without refrigeration. The proposed test is based on gold nanoparticles coated with aptamers. When IL-6 is present, the aptamers will bind the IL-6 and the nanoparticles will aggregate, producing a visible colour change. The test will be simple to perform and practical, without the need for sample pre-treatment and requiring only 20 minutes to complete, making it useful in a wide range of clinical settings.