Multifunctional approach of gold nanostructures coated with silica: combining the diagnosis of circulating cancer cells with the tumor phototherapy

Abstract

This Young Researcher award aims to nucleate a research group in an emerging center, contributing to the decentralization of the state research system. These goals will be achieved through the implementation of an innovative research line, distinct from the previous groups to which I have been associated. Additionally, I intend to establish and consolidate my own research group at an institution that has yet to establish a tradition in this area (FCL/Unesp - Assis), aiming to position it at the forefront of knowledge. The project focuses on the development and application of multifunctional nanostructures for cancer diagnosis and phototherapy. Gold shell-isolated nanoparticles (AuSHINs) will be conjugated with photosensitizers (FS), followed by a second silica shell and functionalization with specific biomolecules for tumor cells. The conjugation will seek for FSs whose electronic excitation and emission are in resonance with the plasmon of AuSHINs, favoring the enhancement of the fluorescent signal (SHINEF, shell-isolated nanoparticles-enhanced fluorescence). This enhancement aims to optimize the performance of nanostructures in sensor applications and achieve a synergistic effect of photothermal therapy (PTT) and photodynamic therapy (PDT). The nanostructures will be applied in the development of SHINEF diagnostic platforms for detecting circulating cancer cells (CCC), isolating traces (from ng/mL to pg/mL) of overexpressed proteins in certain types of cancer. The challenge will be to diagnose such proteins in real samples of blood serum, urine, or saliva from cancer-affected patients, envisioning a less invasive and early diagnosis. Regarding treatment, the nanostructures will be applied as phototherapeutic agents in cells derived from brain, lung, breast, and colorectal carcinomas, in addition to non-tumor cells for comparison. In vitro flow cytometry assays will be conducted to assess the efficiency of the synergistic effect (PTT + PDT), the specificity (biofunctionalization) of nanostructures, as well as the underlying mechanisms involved, such as cell death pathways (apoptosis/necrosis) and reactive oxygen species (ROS) generation. (AU)