Abstract
Multifunctional inorganic luminescent nanostructures are of great interest for future multimodal precision bioimaging applications. Rare earth-doped nanophosphors have attracted special attention in the biomedical field due to their ability to combine optical properties with additional functionalities. Among these systems, magneto-luminescent nanoparticles stand out because they integrate simultaneously magnetic and luminescent properties into a single nanocomposite, thus enabling their use in multimodal biomedical applications. Such nanomaterials have been developed for purposes including their use as contrast agents in bioimaging, magnetic hyperthermia, as well as potential diagnostic and therapeutic strategies through non-invasive approaches. To enhance the physicochemical and biological properties of nanomaterials, mesoporous silica has been employeed as a multifunctional coating, due to their biocompatibility, high surface area, and the presence of surface Si–OH groups, which allow versatile functionalization and further biomedical applications such as drug delivery. In this work, we designed and developed multifunctional nanomaterials composed of different RE-doped nanoparticles combined with superparamagnetic Fe₃O₄ nanoparticles encapsulated in mesoporous silica. Magnetic hyperthermia experiments and cell viability assays demonstrated their potential biomedical applications. Luminescent properties were attributed to the f-f transitions depending on the RE ions, giving rise to intense emission in the UV-Vis region. The encapsulated nanocomposites exhibited a high surface area and superparamagnetic behavior derived from the magnetite component, showing the capacity to generate a significant temperature rise under exposure to an alternating magnetic field. Cell viability assays using the MTT method were conducted in HepG2, hepatic stellate cells (HSC), and Kupffer cells. Our findings demonstrate that RE-doped nanophosphors integrated with superparamagnetic Fe₃O₄ encapsulated in a SiO₂ shell offer a multifunctional nanocomposite that integrates luminescent and magnetic properties with biocompatibility, showing promising potential for future applications in theragnostics.
Biography
Gustavo Alonso Hirata Flores is a distinguished Mexican physicist specializing in the physicochemical properties of nanomaterials. He serves as an Investigador Titular C at the Centro de Nanociencias y Nanotecnología (CNyN) of the National Autonomous University of Mexico (UNAM) in Ensenada, Baja California. Dr. Hirata earned his Bachelor’s degree in Physics from the Universidad Autónoma de Baja California in 1985, followed by a Master’s degree in Materials Physics in 1988 and a Ph.D. in Sciences in 1993 from the CICESE-UNAM Graduate Program. His research focuses primarily on the development of luminescent nanomaterials for applications in solid-state lighting, nanomedicine, and biotechnology. Over his career, he has authored more than 230 scientific publications, including 180 peer-reviewed journal articles, and has supervised 52 theses across undergraduate and graduate levels. Dr. Hirata’s work has been cited over 4,600 times, reflecting his significant impact in the field of nanoscience, particularly in creating innovative luminescent materials for technological and medical applications.
