Scientists have created ‘smart’ contact lenses that have the potential to diagnose cancer at an early stage through tumor-identifying chemicals found in tears.
The device could open the door to an inexpensive “one size fits all” screening program for multiple types of the disease.
The technology captures carriers called ‘exosomes’, which are tiny bubble-like messengers contained within our body’s cells and secreted into blood, saliva, urine and tears.
On the surface are a host of proteins, some of which are fueled by cancer, viral infections or injury.
Exosomes may influence the regulation, progression and spread of tumors, offering hope for more targeted and effective treatment.
Reducing the time to treatment dramatically improves cancer survival rates, with each month without treatment increasing the risk of death by about ten percent.
Project leader Professor Ali Khademhosseini, from the Terasaki Institute for Biomedical Innovation in the United States, where the diagnostic lenses were developed, said: “The lens can detect exosomes in various solutions of various lineages. cells – and human tears.
“They can differentiate surface protein expression as cancer biomarkers.”
The glass is equipped with microchambers linked to antibodies to which the exosomes stick.
In experiments, the device has been successfully tested on exosomes secreted into laboratory fluids from ten different tissue and cancer cell lines, as well as on tears from ten human volunteers.
Professor Khademhosseini said: “The lens can be stained with specific nanoparticle-tagged antibodies for selective visualization.
“This offers a potential platform for cancer pre-screening and a simple, rapid, sensitive, cost-effective and non-invasive supportive diagnostic tool.”
Exosomes were once considered dumping grounds for unwanted materials, but are now known to transport different biomolecules between cells.
Professor Khademhosseini said: “They constitute a rich source of markers that can be targeted for several biomedical applications.
“The methodology that our team has developed greatly facilitates our ability to tap into this source.”
Previous attempts to exploit their importance have been hampered by problems of sufficient isolation to provide enough information.
Current methods involve tedious, complicated, time-consuming and expensive equipment – taking at least ten hours to complete.
The simple technique of the American team eliminates these problems. Additionally, tears are a cleaner and more reliable source of exosomes than other bodily fluids.
The chambers and lens were constructed using direct laser cutting and engraving rather than conventional die casting.
Additionally, they chemically modified the surfaces to activate them for antibody binding.
Standard methods involve metallic or nano-carbon materials in expensive clean rooms.
Exosomes are scanned using a pair of antibodies on gold nanoparticles to visualize potential signs of cancer.
Both are specific for two different surface markers found on all exosomes, Professor Khademhosseini explained.
Further analysis showed that the lens identified exosomes in solutions of three cell lines with different surface markers and using different combinations of antibodies.
Professor Khademhosseini said: “The exosome detection and non-detection patterns of the three different cell lines were as expected.
“It validated its ability to accurately capture and detect exosomes with different surface markers.”
He described the results in Advanced Functional Materials as “encouraging”.
Professor Khademhosseini added that the next generation of smart contact lenses is an “easy-to-use, rapid and non-invasive monitoring platform that holds promise for cancer pre-screening and supportive diagnosis”.