Magnetic nanoparticles coated by natural rubber latex for theranostic applications

• Ano de defesa: 2024
• Autor(a) principal: Vicente, Thiago Tibúrcio
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Aplicações teranósticas; Látex de borracha natural; Magnetic nanoparticles; Nanopartículas magnéticas; Natural rubber latex; Theranostic applications
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/59/59135/tde-28052024-154103/

Magnetic nanoparticles (MNPs) have shown great potential in biomedicine for theranostic (diagnostic and therapeutic) purposes, however, their effectiveness as a contrast agent for ultrasound and photoacoustic imaging (PAI) is limited. In this study, MNPs were synthesized with natural rubber latex (NRL) to improve their behavior as a contrast agent for magnetomotive ultrasound (MMUS) and PAI. We also evaluated the effect of the coating on the calorimetric properties of NPMs as heating mediators in magnetic hyperthermia (MH). NPMs were synthesized by coprecipitation in 3 quantities of NRL: 0 µL (uncoated MNPs), 100 µL (NRL-100) and 400 µL (NRL-400). The MNPs were extensively characterized and their potential for MH was evaluated by calorimetry. Forty-five gelatine phantoms with hemispherical inclusions were produced with different mass concentrations of MNPs and were used for MMUS and PAI measurements. The MNPs had average sizes of 10 to 20 nm, confirmed by X-ray diffractometry and transmission electron microscopy. Magnetic hysteresis curves indicated superparamagnetic samples. NRL-coated MNPs showed increased saturation magnetization, resulting in larger displacements in MMUS. The NRL increased the optical absorbance of the MNPs, resulting in an improvement in the quality of the phantom PA images. From MH, the temperature variation and specific loss power for all MNPs were obtained. This study demonstrates that NRL-coated MNPs are promising candidates for contrast agents in MMUS, PA images and as heat mediators for MH for tumor treatment.