Researchers from the Complutense University of Madrid have participated in the design of an intelligent device made up of nanoparticles capable of killing tumors by releasing a toxic content when stimulated with ultraviolet light through the blood vessels of tumor cells. The system has already been tested in vitro and may prove useful in treating cancers of the esophagus, stomach and skin.
The problem with tumor cells is that, in addition to growing very fast and out of control, they can develop new irregular blood vessels with gaps between 200 and 2,000 nanometers in their surface. These tiny spaces are what the nanoparticles take advantage of to fight the tumor from the bloodstream.
The technique has been developed by scientists from the Complutense University of Madrid, in collaboration with the Center for Biomedical Research in Network for Bioengineering, Biomaterials and Nanomedicine, the Hospital 12 de Octubre Health Research Institute and the Carlos III Health Institute. The key is in the mesoporous silicon nanoparticles, which are biocompatible with the body and that only expel their charge when activated with ultraviolet light.
The study, led by María Vallet-Regí, a researcher at the Department of Inorganic and Bioinorganic Chemistry at the UCM, has been published in the Journal of Materials Chemistry B. The starting point is that tumor cells demand more nutrients due to their rapid growth, which causes the overexpression of some receptors on their surface. The nanoparticles target transferrin receptors, a protein responsible for transporting iron, whose overexpression is 100 times higher in tumor cells than in healthy cells.
In this way, they are able to capture more iron to be able to sustain the high rate of proliferation of solid tumors. To fool malignant cells, the nanoparticles are coated in transferrin. Once they reach the interior of the blood vessels, if they are stimulated with an ultraviolet light, they release the toxic content and cause a cascade cell death . This light activation system has the advantage that it allows you to control and select both the area to be treated and the exposure time.
Furthermore, it can also be applied to internal tumor areas using optical probes. According to the study authors, very small doses kill a large area of tumor. For now, the device has been tested in vitro, in cell lines with neuroblastoma, fibrosarcoma, osteosarcoma, and Ewing’s sarcoma.
The researchers believe that it could be applied to treat tumors that affect the skin, esophagus and stomach, tissues that can be easily radiated with this type of light or, in the case of more internal tumors, with optical probes. Before getting to the clinical part, the next step will be to test the tool in rodents.
