Scientists talked about a blood test that can detect cancer before it appears on the pictures.

Scientists have developed a new photosensitive sensor capable of detecting extremely small amounts of cancer biomarkers in the blood. The technology could potentially detect early signs of cancer and other diseases using a routine blood test. This was reported on February 16 by Science Daily magazine.

Biomarkers are proteins, DNA fragments, and other molecules that can indicate the presence of a tumor, its stage of development, or the risk of disease. However, in the early stages of the disease, the concentration of such molecules is extremely low, and traditional diagnostic methods are not always able to detect them.

"Our sensor combines DNA nanostructures with quantum dots and CRISPR gene editing technology to detect weak biomarker signals using a light-based approach known as second harmonic generation. If successful, this approach can help simplify the treatment of diseases, potentially improve survival rates and reduce overall health care costs," said Han Zhang, head of the study at Shenzhen University.

Scientists claim that the device was able to detect biomarkers of lung cancer in patient samples at the subattomolar level — even with only a few molecules, the system gave a clear measurable signal. The platform is programmable, so in the future it can be adapted to detect viruses, bacteria, environmental toxins or biomarkers of Alzheimer's disease.

According to Zhang, for early diagnosis, this method opens up the possibility of a simple blood test for lung cancer before the tumor becomes visible on CT. He stressed that the method can also help in the development of personalized therapy, allowing doctors to monitor the level of biomarkers daily or weekly and evaluate the effectiveness of treatment, instead of waiting months before the next scan.

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According to the publication, most modern tests require chemical signal amplification to increase the low concentration of molecules, which complicates and increases the cost of analysis. The new system, in turn, makes it possible to detect biomarkers directly, without additional amplification steps.

The method is based on the phenomenon of nonlinear optics, the generation of the second harmonic (SHG), in which light is converted into radiation with half the wavelength. In this design, the process takes place on the surface of a two—dimensional semiconductor, molybdenum disulfide. To precisely place the components, the scientists created DNA tetrahedra— pyramidal nanostructures made of DNA. They keep the quantum dots at a strictly defined distance from the surface of molybdenum disulfide. Quantum dots enhance the local optical field and increase the intensity of the SHG signal.

CRISPR-Cas12a technology is used to recognize specific biomarkers. When the Cas12a protein finds the target molecule, it cuts the DNA strands holding the quantum dots. This leads to a measurable decrease in the SHG signal. Since the method creates virtually no background noise, it provides high sensitivity even at extremely low concentrations of molecules.

To evaluate the effectiveness, the scientists selected miR-21 microRNA, a biomarker associated with lung cancer. After testing in buffer solution, the system was tested on patients' blood serum. Zhang highlighted the excellent results of the sensor, which demonstrated that combining optics, nanomaterials, and biology can be an effective strategy in creating diagnostic devices. According to him, he also ignored similar RNAs and detected only the target marker of lung cancer.

In the future, scientists plan to miniaturize the system. The researchers plan to create a portable version of the device that can be used at the patient's bedside, in outpatient settings, or in regions with limited access to medical care.

On February 10, Science Daily reported on the ability of immune cells to stop fighting cancer. According to the publication, studies have shown that once in the tumor environment, cells begin to produce the CCL3 molecule, which stimulates tumor growth. According to scientists, this is due to the many types of cancer and can be a signal for tracking the progression of the disease.

All important news is on the Izvestia channel in the MAX messenger.