Multifunctional nanoparticles for ultrasound-guided theranostic application

• Autor(a) principal: Arsalani, Saeideh
• Data de Publicação: 2023
• Tipo de documento: Tese
• Idioma: eng
• Título da fonte: Biblioteca Digital de Teses e Dissertações da USP
• Texto Completo: https://www.teses.usp.br/teses/disponiveis/59/59135/tde-30032023-135455/
• topic: Gold nanorods; Hipertermia magnética; Imagem fotoacústica; Magnetic hyperthermia; Magnetic nanoparticles; Magneto-motive ultrasoundImaging; Magnetoacustografia; Nanobastões de uro; Nanopartículas magnéticas; Photoacoustic imaging

Nanoscale materials have been widely explored in various imaging modalities andtherapy due to their remarkable physiochemical properties. For example, magnetic nanoparticles (MNPs) are of great interest for a wide range of biomedical applications owing to their controllable small size, tunable magnetic properties, and biocompatibility. In this thesis, ironoxide nanoparticles (IONPs) were synthesized and characterized, and their potential was investigated in biomedical applications. Firstly, bare IONPs were prepared through an optimized coprecipitation route and coated by polyethylene glycol (PEG) in the post-synthesis procedure. The results showed that both IONPs were highly stable, biocompatible, relatively homogeneous in shape, and free of aggregation. Interestingly, the IONPs coated by PEG exhibited relatively greater magnetization than bare IONPs, which could be attributed to the reduction of surface spine disorder after coating. Moreover, the performance of both MNPs was investigated for diagnostic (magneto-motive ultrasound imaging (MMUS)) and therapeutic (magnetic hyperthermia (MH)) applications. According to the outcomes, PEG-coated IONPs, and bareI ONPs showed an almost similar induced displacement within tissue labeled with MNPs in the MMUS. However, IONPs coated with PEG demonstrated higher heating efficiency than the naked IONPs, which could be the due to the Brownian relaxation time of MNPs after PEG coating. Furthermore, a relatively simple combination of citrate coated manganese ferrite (Ci-MnFe2O4) and cetyltrimethylammonium bromide coated gold nanorods (CTAB-GNRs) was suggested to create hybrid NPs. Because of the oppositely charged surfaces of CTAB-GNRs and Ci-MnFe2O4, an electrostatic interaction occurred, resulting in the formation of small nanoclusters, which increased the contrast of MMUS over just using Ci-MnFe2O4. Moreover, for MH studies, these hybrid NPs not only observed almost similar heating rates as Ci-MnFe2O4 but also its equilibrium temperature was higher than just Ci-MnFe2O4 over time. Moreover, since GNRs are promising contrast agents in optical imaging, these hybrid NPs also examined in photoacoustic imaging (PA) and indicated a strong contrast.