Development of magnetic clays with catalytic activity for cancer treatment application

• Autor(a) principal: Bello, Carolina do Rosário Martins
• Data de Publicação: 2023
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/155199
• topic: Cancer; Catalase; Montmorillonite; Magnetic nanoclays; Magnetic hyperthermia; Peroxidase; Domínio/Área Científica::Engenharia e Tecnologia::Nanotecnologia

Currently, cancer is one of the most widespread diseases with related deaths. Conventional treatments such as chemotherapy and radiotherapy are not targeted at cancer cells, leading to serious side effects for the human body. As technology evolves, new possibilities for cancer treatment arise. In this context, cancer theranostics provides the possibility of having diagnosis and treatment in one only system, improving patient care, and providing customized cancer treatment methods. One of the most promising approaches to theranostics is the use of superparamagnetic iron oxide nanoparticles (SPIONs) as they may be used as contrast agents in magnetic resonance imaging and magnetic hyperthermia, due to the increase of their bulk temperature and their surroundings when an external alternating magnetic field is applied. Not long ago, it was discovered that SPIONs can mimic enzymes such as peroxidase and catalase. Peroxidase-like activity contributes to direct tumour elimination by generating toxic radicals while catalase-like activity leads to conversion of hydrogen peroxide into water and oxygen, helping overcome the hypoxia present in tumour tissues. In this master thesis, SPIONs were coated with 3-amino-propyltriethoxysilane (APTES) and intercalated into Montmorillonite (MMT) nanoclays, and the resulting composite systems were characterized. The incorporation of magnetic nanoparticles in clays and their catalytic activity enables the development of a potential application for cancer treatment. The enzyme-like activity of magnetic nanoclays was evaluated at given pH values, and the influence of the surface coating on the stability of the composites over a week and a month of storage were assessed. Lastly, SPIONs and magnetic nanoclays were submitted to an alternating magnetic field and hyperthermic temperatures were successfully reached. The present work demonstrated that these composite systems possess intrinsic catalase and peroxidase-like activities. With a view to medical application of these materials, further studies are required on their cytotoxicity, as well as more in-depth magnetic hyperthermia assays including various iron concentrations. The properties of the magnetic nanoclays produced indicate their potential as a platform for a future application in cancer theranostics.