Tumour stem cells, from which all other cancer cells derive and which cause the most aggressive cancers, including breast cancer, are particularly resistant to conventional cancer treatments. In this line, researchers from the CIBER of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) of the Drug Delivery and Targeting at the Vall d'Hebron Institute of Research (VHIR) have developed a new therapeutic system where citral, a compound effective against tumour stem cells, is transported in biodegradable nanoparticles.
This study, published in the journal Nanomedicine under the direction of the head of the CIBER-BBN group at VHIR, Dr. Ibane Abasolo, details the process of incorporating citral into nanoparticles (Pluronic F127 polymeric micelles), which stabilise the drug and make it even more effective against tumour stem cells in experimental models of breast cancer. The work has been technologically supported by the Nanbiosis Unit 20, a Unique Science and Technology Infrastructure (ICTS).
Breast cancer is the leading cause of death in women between the ages of 20 and 59, and although its diagnosis and treatment have improved greatly in recent years, relapses and resistance to treatment leave some young patients without a therapeutic option.
According to Marwa M Abu-Serie, an Egyptian researcher who carried out the study during her stay at VHIR, "we have found that the combination of these polymeric micelles of citral with paclitaxel, a first-line chemotherapy drug for breast cancer treatment, is beneficial and could prevent the appearance of relapses".
Conventional cancer treatments, such as paclitaxel, tend to kill the faster-growing tumour cells, but not so much the slower-growing tumour stem cells. The combination of citral micelles with paclitaxel has been shown, in cell cultures, to act together on both tumour stem cells and the rest, avoiding the increase that usually occurs in the proportion of tumour stem cells when treatment is carried out exclusively with cytostatic drugs such as paclitaxel.
The director of this CIBER-BBN study, Ibane Abasolo, believes that this opens up a hopeful path to "improve the management of the most aggressive breast cancers, by being able to combine standard chemotherapy with nanoformulations".
Therefore, the nanoencapsulation of citral allows not only a direct effect on tumour stem cells but also synergism with existing chemotherapeutics, paving the way towards the complete eradication of cancer, although "further studies will be needed to deepen the cellular and molecular mechanisms of such synergy and to further validate the results of cell culture in appropriate animal models", says the researcher.
The CIBER (Center for Biomedical Research Network Consortium, M.P.) depends on the Carlos III Health Institute –Ministry of Science and Innovation- and is co-financed by the European Regional Development Fund (ERDF). The CIBER of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) is made up of 46 research groups, selected on the basis of their scientific excellence, working mainly within three scientific programmes: Bioengineering and Biomedical Imaging, Biomaterials and Tissue Engineering and Nanomedicine. Its research is oriented towards the development of prevention, diagnosis and monitoring systems as well as technologies related to specific therapies such as Regenerative Medicine and Nanotherapies.