'Spray' sensors under study for lung cancer diagnosis

“Spray” to stimulate the process that can lead to Detecting lung cancer early. This is the strategy that a team of researchers from MIT (Massachusetts Institute of Technology) is working on: inhalable nanosensors, which can be delivered via an inhaler or nebulizer. If these smart particles encounter tumor-associated proteins, they produce a signal that accumulates in urine, where they can be detected by a simple test, such as one performed with a test paper strip.

This approach, based on a new technology developed at MIT, could replace or combine the current gold standard for lung cancer diagnosis, low-dose computed tomography (CT), experts suggest by presenting the results of their work published in the journal Progress. scientific”. a task: Making diagnosis as easy as using a spray. They believe this could have a particularly significant impact in low- and middle-income countries where CT scanners are not widely available. “Around the world, cancer will become increasingly prevalent in low- and middle-income countries. The epidemiology of lung cancer is linked to pollution and smoking, so we know that these are environments where access to this type of technology can have a significant impact,” says Sangeeta Bhatia, senior The authors of the study (which includes Qian Zhong and Edward Tan as lead authors).

Bhatia has spent the past decade developing nanosensors for use in diagnosing cancer and other diseases, and in this study, she and her colleagues explored the possibility of using them as a more accessible alternative to CT scanning for lung cancer. These sensors consist of polymeric nanoparticles coated with a type of DNA “bar code,” which is separated from the particle when the sensor encounters enzymes called proteases, which are often overactive in tumors. These barcodes eventually accumulate in the urine and are eliminated from the body.

Previous versions of the sensor, which targeted other tumor sites such as the liver and ovary, were designed to be administered intravenously. For lung cancer diagnosis, the researchers wanted to create a version that could be inhaled, which might be easier to implement in low-resource settings. “When we developed this technology, our goal” was also “to lower the threshold of accessibility, in a way that we hope will improve resource disparities and inequalities in early lung cancer detection,” notes Chung. Thus two formulations were created: a solution that can be sprayed and administered using a nebulizer, and a dry powder that can be administered using an inhaler.

Once the particles reach the lungs, they are absorbed into the tissues, where they encounter any proteases that may be present. Human cells can express hundreds of different proteases, some of which are overactive in tumors. These cancer-causing proteases detach the barcode from the sensors, allowing it to circulate in the bloodstream until it is excreted in the urine. In previous versions of this technique, researchers used mass spectrometry to analyze a urine sample. In the new version, they have created the lateral flow test, which allows you to detect barcodes using a simple paper test strip designed to detect up to 4 different DNA barcodes, each indicating the presence of a different protease. “The idea was to be able to put the sample directly on the paper and read it within 20 minutes,” Bhatia says.

The researchers tested their diagnostic system on mice genetically modified to develop lung tumors similar to those seen in humans. The sensors were used 7.5 weeks after tumors started forming, a time point likely associated with stage I or II cancer in humans. A group of four that can provide accurate diagnostic results has been tested and found that it can accurately detect lung cancer in the early stages. For use in humans, more sensors may be needed to get an accurate diagnosis, but that could be achieved by using more strips of test paper, say researchers who now plan to analyze human biopsy samples to see if the sensor panels they use will work. . In the long term, they hope to conduct clinical trials on patients. “The idea is to get an answer as to whether follow-up testing is needed or not, and we can get patients with early infections into the system so they can receive curative surgery or life-saving medications,” Bhatia concludes.

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