Exploring the potential sorbent capacity of iron nanostructures to isolate urinary endogenous metabolites

• Autor(a) principal: Santos, Mariana Pereira
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.13/2634
• topic: Biomarkers; Cancer; Maghemite; Magnetite; NMR; Sorption capacity; Biomarcadores; Maghemita; Magnetita; Capacidade de sorção; .; Faculdade de Ciências Exatas e da Engenharia; Domínio/Área Científica::Engenharia e Tecnologia::Nanotecnologia

Cancer, one of the deadliest diseases of the world, is characterized by metabolic alterations that cause cells abnormal growth resulting in an uncontrollable proliferation. To reduce the mortality, increase the life quality and make the treatment more effective, early diagnosis is essential. Metabolomics is a promising area regarding cancer early diagnosis that detects a specific metabolite profile from biological samples using “case control” studies. This profile consists of a panel of small molecules derived from a global or target analysis that is detected through high-resolution analytical methods like the proton nuclear magnetic resonance (1H NMR). Urine is an appealing biofluid, obtained by a non-invasive way, rich in metabolites that reveals the recent homeostatic condition of an individual. Magnetic nanoparticles (MNPs), namely the magnetite (Fe3O4) and maghemite (Fe2O3) have been widely used in oncology for tumour targeting and contrast agent for magnetic resonance image diagnosis. However, their uncoated sorption capacity towards cancer biomarkers remains unknown. In this work, we aimed to evaluate the sorption capacity of uncoated magnetite and maghemite towards the extraction of different metabolites potential cancer biomarkers present on urine using the magnetic solid phase extraction followed by 1H NMR. To achieve this, the extraction methodology was optimised using spiked synthetic urine regarding the MNP type, amount, extraction time and temperature. The best optimization results were applied on urine samples of lymphoma and breast cancer patients and healthy volunteers to identify and quantify the potential biomarkers on a “case-control” study. Regarding the results, the 20-30 nm magnetite showed best cost-effectiveness ratio being the optimal extraction conditions obtained by using: a ratio of 0.2 mg/ml to extract during 5 min at room temperature with the addition of 1 ml of ultrapure water as elution solvent. On “case-control” study, most of the potential biomarkers followed the same changes, regardless of the cancer type. Keywords