Synthesis, Characterization, and Toxicity Evaluation of Superparamagnetic Iron Oxide and Bimetallic Fe¿O¿@Au Nanoparticles for Biomedical Applications.

• Grant number: 25/05376-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2025
• End date: July 31, 2026
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Paula Silvia Haddad Ferreira
• Grantee: João Vitor Pinheiro do Carmo
• Host Institution: Instituto de Ciências Ambientais, Químicas e Farmacêuticas (ICAQF). Universidade Federal de São Paulo (UNIFESP). Campus Diadema. Diadema , SP, Brazil

Abstract

This project explores two research approaches involving nanostructured systems with biomedical applications. The first focuses on the synthesis, characterization, and biological evaluation of superparamagnetic iron oxide nanoparticles (SPIONs), specifically magnetite (Fe¿O¿), coated with biocompatible ligands containing free thiol groups, such as glutathione (GSH), aiming to anchor bioactive molecules to these carriers. The second approach targets the development of bimetallic Fe¿O¿@Au nanoparticles, where the incorporation of gold onto the SPIONs' surface enhances their chemical stability and introduces unique optical properties.SPIONs will be synthesized using the coprecipitation method, involving iron salt precipitation with the addition of a weak base, such as ammonium hydroxide. Different SPIONs: GSH mass ratios and temperature and reaction time variations will be tested to optimize the coating. These nanoparticles will be employed for anchoring anti-inflammatory drugs, both natural (such as banana oil) and synthetic (such as acetylsalicylic acid).Bimetallic Fe¿O¿@Au nanoparticles will be synthesized via chemical reduction, using a strong reducing agent to promote gold deposition onto the SPIONs' surface. Characterization will include structural, morphological, magnetic, and optical analyses, such as UV-Vis spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), magnetic curves, and studies on the efficiency of ligand functionalization on the nanoparticles' surface. The behavior of these carriers in aqueous dispersion will be assessed using dynamic light scattering (DLS) and zeta potential measurements. Finally, the cytotoxicity and genotoxicity of the most promising nanoparticles will be evaluated in both healthy and cancer cells, aiming at their potential application in innovative therapies.