Vanadium (V), the number 23 element of group five of the periodic table, has as peculiar characteristic: it is attracted to cancer cells. This property interested Dr. Francisco J. Melendez-Bustamante and his Master’s degree student on Chemical Sciences at the Autonomous University of Puebla (BUAP), Lisset Noriega de los Santos. So, they designed a project to use vanadium compounds to design drugs, through methods based on theoretical chemistry, to support the treatment of breast cancer.
“We study vanadium complexes, attached to Schiff bases. What these complexes do is acting as photosensors in a photodynamic therapy. In turn, the Schiff bases are organic compounds containing a double bond carbon-nitrogen, RR’C = NR“, where R and R“ are alkyl or aryl groups, while R’ is a hydrogen atom, forming a stable imine called Schiff base”, explains in an interview Dr. Melendez-Bustamante.
In photodynamic therapy, a drug transformed in photosensitive molecule is applied in the patient, which adds up in damaged cells. Then with a laser beam the drug is activated, eliminating only those cells, with low side-effects.
“Vanadium has a very interesting feature; it has a great affinity with cancer cells. Especially, the vanadium compounds are used as molecular probes. Once injected into the human body, they deposit on the cancerous or damaged cells; and because they are attached to a Schiff base, they work as a photosensor. Then, [the area is] radiated with a wavelength (between 400 and 800 nanometers, nm) the compound; and since vanadium is not within that wavelength, the Schiff base produces free radicals that will specifically attack the cancer cells, eliminating them in this process,” says Dr. Melendez-Bustamante.
Dr. Meléndez Bustamante explains that in this project the electronic structure, molecular orbitals and electronic transitions are being calculated to know whether the vanadium complexes bound to Schiff bases may be future photosensors.
Through this phototherapy, the patient would receive an alternative treatment that does not cause secondary damages or discomforts such as those produces by chemotherapy or radiation. In this regard, he said that phototherapy is a selective radiation that does not harm other cells and its side effects are reduced to possible slight excoriations or rashes in the skin, which can even be avoided following certain medical recommendations.
“What we basically do in the Theoretical Chemistry Laboratory is computational quantum chemistry. We do simulations using the LNS-BUAP supercomputing equipment. We first study biomolecular systems with pharmacological properties from the computational point of view,” he says.
“Once we know what possible drugs may interact with the chosen biological targets (receptors), what follows is […] attempting to synthesize the complexes and subsequently test them on laboratory animals, to then do pharmacological tests and conclude whether these compounds could be first- and second-generation drugs. ”
Source: Agencia Informativa CONACYT