The sensor marks the edge of the tumor very precisely, while allowing only minimal damage to healthy tissues * The study was recently published in the scientific journal Theranostics
A multidisciplinary research group led by Prof. Ronit Sachi-Painero, head of the Department of Physiology and Pharmacology at the Sackler Faculty of Medicine at Tel Aviv University, has developed a smart nanometer sensor that acts as a switch that turns on fluorescent light in the presence of cancer cells. The sensor marks the tumor and its edges with a particularly high level of accuracy, thus allowing surgeons to remove the tumor in its entirety - with minimal damage to the healthy tissues around it, and without leaving malignant cells in the body, which may redevelop and/or send fatal metastases to other organs. The meaning: a considerable increase in the percentage of survival and the chances of recovery of the operated.
The research was led by Rachel Blau, Jana Epstein and Yevgeny Pisarevski, PhD students from Prof. Sachi-Painero's laboratory. The study was published in May 2018 in the scientific journal Theranostics.
Prof. Sachi-Painaro explains: "In the new study, we based ourselves on previous studies, in which we discovered a unique characteristic of a variety of cancerous tumors: increased expression of enzymes called cathepsins. The function of these enzymes, which are found in a much smaller amount even in healthy cells, is to identify and cut a certain sequence of amino acids (the building blocks of proteins). We took advantage of this feature to build a smart sensor that will identify and label cancer cells."
How It Works? The researchers produced polymeric nanoparticles, consisting of the same sequence of amino acids that the cathepsins are designed to cut. These particles were attached to fluorescent tags made of molecules of the dye cyanine (Cy). "When the cyanine molecules are held together by the polymer particle, the light waves they emit cancel each other out, and they remain dark," says Prof. Sachi-Painero. "But as soon as the nanoparticle reaches a cancer cell, the connecting polymer is cut by the cathepsins, and the cyanine molecules move away from each other, shining with a glowing light. In contrast, in the surrounding healthy tissue, the polymer is not cut, and the area remains dark. The border between the bright area (the tumor) and the dark (healthy cells) is very clear to the eye." In professional terms, this means that the smart sensor has high sensitivity - it detects all cancerous cells, and also high selectivity - it does not tag healthy cells. In this way, it reports to the surgeon the location of the cancer cells in real time, that is, during the surgery itself - below the detection threshold of the imaging methods available today.
The groundbreaking research was carried out in collaboration with Prof. Zvi Ram, head of the neurosurgery department at the Ichilov Hospital, and his deputy Dr. Rachel Grossman. In the first stage, it was proven that the enzyme that activates the sensors does exist and is more pronounced in tissues that were excised from patients in the operating room and transferred to the laboratory. Later, the researchers used mouse models for breast cancer and melanoma skin cancer, which tend to metastasize to the brain and lungs. The mice were divided into two main groups: some were operated on to remove the tumor under normal white light, without additional aids, while the other group was injected with the new sensor before the operation.
The results were extremely promising: in the mice that were operated on without the sensor, metastases or a recurrence of the tumors themselves were diagnosed within a short time, and their life expectancy was short - only 40% of the mice in this group survived 120 days after the operation. In contrast, when the surgery was performed with the help of the new sensor, the survival of the mice was double: 80% of them remained healthy after 120 days. In other words: 60% of the mice operated on with the 'normal' surgery eventually died of the disease, compared to only 20% of those operated on using the smart sensor.
In addition, the new sensor was also compared to two sensors that are currently in clinical trials in operating rooms. It was found that its levels of sensitivity and selectivity are higher, and it even lights up much faster. At the therapeutic level, this means that the patient does not need to be hospitalized the day before, and it is possible to inject the sensor only about 4 hours before the operation.
"We registered a number of patents for the development," concludes Prof. Sachi-Painero, "and now we are negotiating with a number of pharmaceutical companies, with the aim of advancing to the stage of clinical trials, and later to production in commercial quantities. We believe that our smart sensor can lead to a real improvement in the results of surgeries to remove cancerous tumors, and significantly increase the patients' chances of surviving the disease."
Prof. Doron Shabat from the School of Chemistry at Tel Aviv University and Prof. Galia Blum from the Faculty of Medicine at the Hebrew University also participated in this study.
This research was funded by the European Union (ERC), the National Science Foundation, the Ministry of Science and the Cancer Society.
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with gratitude
Avi Blizovsky
Response to commenter Kaiser Souza to the editor.
Why is it that even in the journal of the science they publish this kind of anti-Semitic comments in which we are bombarded above all written and electronic publications. It is interesting to know what the above-mentioned writer's reaction was to a sentence of the form: "I read that the Jews with crooked noses decided to expel their Sephardic brothers from the elite meetings" and likewise the opinion of the respected editor that it is possible to publish such things.
It's just a shame and unnecessary.
I read that the Palestinians are trying to get us out of the European science program.
The beauty here is the genetic hatred of the Europeans for the Jews and there is a possibility that the move will succeed. And that's good..
Because then we will further strengthen the relationship with China and the USA and forget about 2 fictitious entities that will be sent to the historical dustbin (the European Anti-Semitic Union and the average Palestinian people)
Well done !!!!