Extracellular hyperthermia for the treatment of advanced cutaneous melanoma

• Autor(a) principal: Simões, Beatriz Traguedo
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/134706
• topic: endocytosis; magnetic hyperthermia; melanoma; nanotechnology; small-molecule inhibitors; superparamagnetic iron oxide nanoparticles; Domínio/Área Científica::Engenharia e Tecnologia::Nanotecnologia

Nowadays, nanoparticles (NPs) are a promising approach to improve the efficiency of cancer therapies. Magnetic fluid hyperthermia is an emerging alternative to drug-dependent treatments, based on the application of an alternating magnetic field (AMF) in superparamagnetic iron oxide nanoparticles (SPIONs), promoting cell death by local heat dissipation. However, studies have shown that when SPIONs are internalized by cancer cells their magnetic-responsive properties change, ultimately reducing their heating capacity. Here, we aim to improve magnetic hyperthermia treatment efficiency by blocking the SPIONs internalization with small-molecule inhibitors of endocytosis (SMI). To study endocytosis, the internalization of SPIONs was assessed in a cell line of advanced cutaneous melanoma (WM983b). A time-course analysis of SPIONs internalization was performed in single-cell suspension model, 2D and 3D in vitro cell models. Due to the SPIONs surface charge influence in the cellular uptake mechanisms, studies were performed with SPIONs stabilized with dimercaptosuccinic acid (DMSA) (anionic NP) and 3-aminopropyl)triethoxysilane (APTES) (cationic NP) surfactants. Results demonstrate a rapid interaction between SPIONs and the cell membrane, more pronounced for cationic SPIONs. By labelling the APTES coated SPIONs with Rhodamine B fluorophore (RhoB), the blocking of cellular uptake was assessed by fluorescence microscopy. The inhibition of SPIONs_RhoB internalization was achieved with methyl-β-cyclodextrin endocytic inhibitor allowing only 14% of cellular uptake, suggesting receptor-mediated endocytosis as the uptake mechanism. In vitro magnetic hyperthermia was performed and the inhibition of the SPIONs internalization improved the NPs heating efficiency (SAR value of 91 ± 16 W/g) compared to intracellular hyperthermia (SAR value of 63 ± 7 W/g). Further studies are needed to evaluate the effects on cell death by apoptosis. Here, we show that the inhibition of NPs uptake is an effective approach to improve magnetic hyperthermia therapy. Besides, knowing the endocytic mechanism brings the possibility to develop new combined therapies by controllable endocytosis. However, more studies are required to accurately determine the specific endocytic route taken.