Plasmonic nanostructures for synergistic photodynamic (PDT) and photothermal (PTT) therapy of cancer cells

Abstract

Grand challenges such as the identification of more efficient and less invasive drugs for cancer therapy can only be faced with concerted efforts in multidisciplinary research. In this project, we gathered a multiinstitutional team of physicists, chemists and biologists to develop plasmonic nanostructures aiming phototherapeutic applications in cancer cells. Specifically, gold shell-isolated nanoparticles (AuSHINs) will be conjugated to organic photosensitizers (FS) seeking synergy between photodynamic (PDT) and photothermal (TFT) therapies. Furthermore, specificity to tumor cells will be conferred to the nanostructures with the anchoring of specific antibodies. The goal will be to obtain highly efficient nanostructures in the photosensitization of cancer cells, generating little or no impact on the viability of non-tumor cells. We shall carry out in vitro assays using a wide panel of cells, derived from breast (MCF7, BT474), lung (A549), oropharynx (Hep-2), colorectal (Caco-2) and melanoma (A375 and SH-4) carcinomas, in addition to non-tumor cells collected from peripheral blood of donors. The efficiency and specificity of the nanostructures will be quantified via flow cytometry, which will also determine the cell death pathways (apoptosis vs necrosis) triggered. In a second part of the work, model systems of plasma membrane of tumor and non-tumor cells will be assembled using Langmuir and Langmuir Schaefer (LS) films, where the nanostructures will be incorporated and further photoactivated. The goal will be to investigate the effects of hyperthermia and lipid oxidation on the physicochemical properties of the membrane, which include the increase in surface area and cleavage of carbon chains. In addition to the traditional surface pressure (À) measurements, vibrational spectroscopy techniques will be applied to the Langmuir (PM-IRRAS) and LS (FTIR) films in order to elucidate the reaction mechanisms at the molecular level. The final goal will be to correlate the discoveries made at molecular scale with photodynamic efficiency in complex systems involving the in vitro culture of cancer cells. Taken together, these results will contribute to the development of more efficient and less invasive therapeutic nanomaterials, which is relevant not only for applications in phototherapies (PDT and TFT), but also for many other fields of life and health sciences. (AU)