Modelación de la tasa de intercambio del agua en el agente de contraste bioactivado [Gd (DOTA-FPG) (H2O)], con uso en la identificación de expresión génica en células cancerígenas

Abstract

Objective: modeling of the water exchange rate for bioactivated agents used in nuclear magnetic resonance, a technique implemented in medicine for diagnostic and treatment purposes to identify gene expressions in cancer cells.using atomistic molecular dynamics it is possible to extract two of the three parameters that determine how efficient a contrast agent is. Molecular dynamics (MD) is an excellent tool for evaluating in-silico contrast agents. LAMMPS software is used to study chemical compounds (contrast agents), implemented in the HPCC (High Performance Computing Clusters) cluster with 8 nodes, GNU/Linux operating system, IDE or ATA storage capacity: 66MB/s speed, located at the Universidad San Francisco de Quito. In this particular case using [Gd(DOTA-FPG)(H2O)], as a model, and substituting the Gd ion by Ca it has been found that the increase of proton relaxation is given by the ion (calcium), applied field (internal and external), metabolism of the human body, pH, enzyme of use and in turn the relaxivity. In the measurement of the water exchange rate at 2.5 Å called first sphere we found a presence of 1 water molecules interacting with the contrast agent to fulfill its function. By comparing the modeled values of water exchange rates with experimental values we can conclude by establishing a screening method for new agents based on this parameter and others that can be calculated from the same results. It is recommended for its calculation to carefully simulate the movement of water molecules and style around the contrast agent by validating the variation of water exchange rate of a bioactivated Gd complex (contrast agent that in addition to improving the image resolution, is activated at the site where an enzyme is present as a substrate.