Scientists Develop Smart Contact Lenses (ACSM-CL) That Can Diagnose Cancer

A team of researchers from the Terasaki Institute for Biomedical Innovation (TIBI) has created a contact lens that can collect tears and examine chemicals in them to diagnose cancer.

Antibody-Conjugated Signaling Microchamber Contact Lens. Credit: Terasaki Institute for Biomedical Innovation

The smart contact lenses will help to detect the presence of exosomes in tears. These extracellular vesicles found in body secretions are potential biomarkers to target for cancer diagnosis, scientists say.

The lens, which is called the antibody-conjugated signaling microchamber contact lens (ACSM-CL), comes with microchambers that are bound to antibodies for collecting exosomes in tears. It can be stained with nanoparticle-tagged antibodies to enable visualization of cancer signs, as per the scientists.

“Exosomes are a rich source of markers and biomolecules which can be targeted for several biomedical applications,” said TIBI’s director Ali Khademhosseini, Ph.D. “The methodology that our team has developed greatly facilitates our ability to tap into this source.”

These smart lenses promise to enable the detection of cancer in its early stages of development. They look to provide a fast, sensitive, and yet non-invasive diagnostic tool.

Exosomes for cancer diagnosis

The membrane-bound exosomes are made within most cells and released into different bodily fluids, including tears, saliva, and urine. In the past, they were considered to be what unwanted materials from cells are dumped in. But scientists now know that there is more to these vesicles.

Exosomes aid in carrying diverse biomolecules between cells. There is also evidence that they boast abundant surface proteins, some of which increase in response to an injury, infection, or cancer. Furthermore, exosomes from tumors have a strong impact on tumor control, growth, and metastasis.

Researchers have, therefore, shown interest in exploiting exosomes for cancer diagnosis as well as for treatment or prognosis estimation due to their capabilities. A major challenge they have faced, however, is that of isolating the vesicles in needed quantity and purity. Exosomes are hard to isolate and current techniques are taxing and slow.

The difficulty in using exosomes for cancer detection also has to do with costs. Popular techniques for detecting isolated exosomes demand the use of costly and massive equipment.

The new smart contact lenses look to help surmount these major challenges.

Making a rapid, cost-effective cancer diagnostic tool

Tears provide a better, purer source of exosomes, compared to saliva, blood, or urine. The scientists involved in this research drew on their contact lens biosensor design and building knowledge to make isolation from this source possible.

The team relied on alternative approaches for the production and optimization of the ACSM-CL. For example, instead of using traditional casting mold, it employed direct laser cutting and engraving in the making of the lens’s microchambers. The scientists also used a technique that chemically adapted and activated microchamber surfaces for antibody binding, thus avoiding more-costly standard approaches.

Khademhosseini’s team optimized procedures for sticking a capture antibody to the microchambers of the lens and a detection antibody to gold nanoparticles to enable spectroscopic visualization. These two antibodies are specific to two distinct surface markers present on all exosomes, the researchers said.

The contact lens was successfully tested against exosomes that were secreted into supernatant liquids from 10 separate tissues and cancer cell lines. Similar results were also recorded when it was tested on tears from 10 volunteers.

The scientists went further to test the ACSM-CL on exosomes in solutions obtained from three separate cell lines having distinct surface markers, together with varied marker-specific detection antibody combinations. The lens correctly identified exosomes with dissimilar surface marker expressions.