Towards the development of a nanoparticle for early diagnosis of Alzheimer’s Disease, based on the reversible translocation of the blood brain barrier.

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Enhancing the magnetic properties of superparamagnetic iron oxide nanoparticles using hydrothermal treatment for magnetic hyperthermia application

Publication . Martins, Carla; Rolo, Catarina; Cacho, Vanessa R. G.; Pereira, Laura C. J.; Borges, João Paulo; Silva, Jorge Carvalho; Vieira, Tânia; Soares, Paula I. P.; CENIMAT-i3N - Centro de Investigação de Materiais (Lab. Associado I3N); DCM - Departamento de Ciência dos Materiais; DF – Departamento de Física; RSC - Royal Society of Chemistry

Superparamagnetic iron oxide nanoparticles (SPIONs) are the most commonly used inorganic nanoparticles for magnetic hyperthermia in cancer treatment. In this technique, the temperature of the tumor is increased by applying an external alternating magnetic field, which induces heat release from magnetic nanoparticles located at the tumor site. In this study, SPIONs were produced using the chemical co-precipitation technique combined with hydrothermal treatment to reduce their size dispersibility and increase their crystallinity, which are directly related to their magnetic properties. The size of the SPIONs increased from 9 nm to 20 nm after hydrothermal treatment at 160 °C for 24 h. These NPs exhibit a cubic/rectangular shape with a structure composed of both magnetite and maghemite. Their superparamagnetic behavior was confirmed, and the magnetic saturation increased from 58 to 73 emu g−1 at RT and from 67 to 81 emu g−1 at 10 K. Magnetic hyperthermia measurements showed an increase in SAR values from 83 to about 160-200 W g−1, depending on the hydrothermal treatment conditions. Additionally, the exposure of normal and melanoma cells to SPIONs in the presence of an alternating magnetic field leads to a significant reduction in cell viability, with a more pronounced effect in melanoma cells. These results demonstrate the high potential of this synthesis technique for producing SPIONs for cancer treatment via magnetic hyperthermia.

2025-02-10Artigo científico

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Optimizing magnetic hyperthermia for melanoma

Publication . Simões, Beatriz T.; Chaparro, Catarina; Vieira, Tânia; Valente, Manuel A.; Cavaco, Marco C. V.; Neves, Vera; Silva, Jorge C.; Borges, João Paulo; Almeida, Filipe V.; Soares, Paula; DCM - Departamento de Ciência dos Materiais; CENIMAT-i3N - Centro de Investigação de Materiais (Lab. Associado I3N); DF – Departamento de Física; IOP Publishing

Superparamagnetic iron oxide nanoparticles (SPIONs) are widely used in magnetic hyperthermia, where their therapeutic efficacy depends on efficient heat generation. However, intracellular uptake of SPIONs has been shown to reduce their heat dissipation capacity, limiting hyperthermia performance. To address this challenge, we explored the use of small-molecule endocytosis inhibitors to block SPIONs’ uptake in vitro. SPIONs stabilized with 3-aminopropyl triethoxysilane (APTES) were evaluated in an advanced cutaneous melanoma cell line treated with a small library of endocytosis inhibitors. Among these, methyl-β-cyclodextrin significantly reduced SPIONs’ uptake compared to untreated cells. Importantly, uptake inhibition restored SPIONs’ heat dissipation capacity from specific absorption rates of 63 to 91 W g−1 and improved the temperature increase by 2.6 °C, under magnetic hyperthermia conditions. These findings demonstrate that targeting nanoparticle internalization with small-molecule inhibitors, particularly methyl-β-cyclodextrin, enhances the efficiency of magnetic hyperthermia in melanoma cells. This strategy offers a promising approach to optimize magnetic hyperthermia for melanoma treatment.

2025-03-20Artigo científico

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Entidade financiadora

Fundação para a Ciência e a Tecnologia

Programa de financiamento

Concurso de Projetos IC&DT em Todos os Domínios Científicos

Número da atribuição

PTDC/BTM-MAT/2472/2021