Researchers from the Drug Delivery and Targeting group of the CIBBIM-Nanomedicine at Vall d'Hebron Institute of Research (VIHR), have evidenced that targeted nanomedicines improve treatment sensitivity of breast and colon cancer stem cells. To be able to study the efficacy of the nanomedicines, researchers have developed a novel fluorescent model that allowed them to visualize these cells and deliver the treatment. The landmark has been published as featured article of the November issue of http://www.nanomedjournal.com/article/S1549-9634%2815%2900152-5/abstract" Nanomedicine: NBM journal.Cancer stem cells are a minor cell subpopulation within the tumor cells that retain the capacity of survival in any part of the body. They are very aggressive, do not respond to the vast majority of conventional cancer treatments and are the responsible of the metastasis because they have a great capacity to migrate, to invade and to restrain the mechanisms of cell death.One of the main difficulties of researchers is to combat these cells, because it is very difficult to distinguish them. The principal investigator of the study, Dr. Simó Schwartz Jr., explains that they have genetically modified these cells in order to emit a light that differentiate them from the rest. "With the new fluorescent system, we can easily isolate and study cancer stem cells, so we can identify new biomarkers and to prove and improve therapies", he says.Dr. Schwartz Jr's group is specialized in the use of nanotechnology to improve the treatment and diagnosis of cancer. Nanotechnology enables the drug transportation, in nanoconjugates, to the specific receptors of the cells. Therefore, the treatment is more effective, because it arrives with a major concentration, and less toxic because it is directly delivered into the malignant cells.After identifying the cancer stem cells, VHIR researchers, in collaboration with researchers from the University of Lisboa, tested in vitro the efficacy of the nanomedicines in two cancer models. They chose colon and breast cancer because they are currently working with these lines in the lab and they know the specific receptors of these stem cells."We have demonstrated that if we administer the conventional therapies against breast and colon cancer as nanoconjugates, the treatment is more effective and we can eliminate those cancer stem cells which are resistant to chemotherapy", explains Dr. Schwartz Jr. His next challenge will be to demonstrate the efficacy of these nanomedicines in in vivo models, using the same system of fluorescence.The new methodology is also able to identify those cancer stem cells that can be derived to normal cancer cells and vice versa. This is one of the main problems of the scientific community, because the mechanisms involved in this process of reconversion are yet unknown. Now, Dr. Schwartz hopes that with the new fluorescence system they will be able to study this process and to design specific therapies to block it.