Inhalable sensors could help detect lung cancer

Early diagnosis is often synonymous with a cure for many types of cancer. A technology developed by MIT could be another tool in this battle for health, specifically against lung cancer, by inhaling nanoparticle sensors followed by a urine test.

Entering the body via an inhaler or nebuliser, these diagnostic sensors produce signals that accumulate in the urine when they encounter proteins linked to lung cancer. These signals can then be detected using a simple test strip specifically for the examination.

The good news is that this method is a potential substitute or complement for the current gold standard for lung cancer diagnosis, computerised tomography. If realised, this possibility will have a significant impact on developing countries with limited availability of CT scanners, say the researchers responsible for the innovation.

According to the study, the death rate from lung cancer continues to fall in countries with a high development index (HDI), partly due to substantial advances in early detection and treatment tools. However, there is still a disproportionately high mortality rate in countries with low and medium levels of purchasing power, a fact that correlates with the detection of the disease at an advanced stage. Hence the importance of access to this type of more affordable technology, such as inhalable sensors.

The researchers have spent the last decade developing nanosensors for use in diagnosing cancer and other diseases and, in this study, they explored the possibility of using them as a more accessible alternative to CT scan screening for lung cancer. Previous versions of the sensors, which targeted other organs with suspected cancer, such as the liver and ovaries, were designed to be administered intravenously. For the diagnosis of lung cancer, the researchers wanted to create a version to be inhaled, making it easier to use in locations with few resources.

The sensors are made up of polymer nanoparticles coated with “DNA barcodes”. These particles are absorbed by lung tissue, where they can come into contact with enzymes called proteases, which are overactive in tumours. These malignant proteases break the DNA barcodes of the sensors and allow them to circulate through the body until they are eliminated in the urine.

The researchers have created two formulations of these particles: one in aerosol form that can be administered with a nebuliser, and one as a dry powder that can be administered via an inhaler.

The researchers tested the novelty on mice genetically modified to develop lung tumours similar to those seen in humans. The sensors were administered 7.5 weeks after the tumours began to form, a time that probably correlates with stage 1 or 2 cancer in people.

In the first set of tests, 20 different sensors were used. Using a machine learning algorithm, the researchers identified a combination of just four sensors that could provide accurate diagnoses. In the case of humans, more sensors may be needed to guarantee accurate results.

The researchers now plan to analyse human biopsy samples to see if the sensors would also work to detect cancers in people. In the long term, they hope to carry out clinical trials on human patients.

The company Sunbird Bio has already carried out phase 1 tests with a similar sensor for use in diagnosing liver cancer and a form of non-alcoholic hepatitis. An article on the innovation was published in the journal Science Advances earlier this year.

According to Polaris Market Research, the global market for disposable medical sensors is expected to grow from $10.4 billion in 2023 to $42.4 billion in 2032, representing a compound annual growth rate of 16.9 per cent over the period. Disposable medical sensors are those used to diagnose, monitor and control a series of physiological characteristics in patients and which are discarded after use.