Engineering a multi-stimulus responsive nanofibrous membrane for cancer treatment

• Autor(a) principal: Oliveira, Leonor Nunes da Cunha Castro
• 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/10362/152858
• topic: Cancer; Electrospinning; Thermoresponsive polymer; Domínio/Área Científica::Engenharia e Tecnologia::Outras Engenharias e Tecnologias

Cancer is one of the most common causes of death in the world and current treatments are usually insufficient and present many gaps, leading to a will to cross the limitations and find new methods of treatment. Thereby, the development of new cancer treatment options is one of the most studied research areas, particularly in development of stimuliresponsive systems for localized and controlled drug delivery systems. The incorporation of magnetic nanoparticles (MNPs) in thermoresponsive nanofibers enables the development of dual responsive systems with significant applications in cancer therapy such as magnetic hyperthermia and controlled drug delivery. This thesis’ objective is to engineer a stimuli-responsive nanofibrous membrane for cancer treatment. To reach this purpose, a thermoresponsive polymer (p(MEO2MA-co- OEGMA)) was processed, optimized and characterized with the aim to produce electrospun nanofibers with the ability to respond to temperature in the ranges of magnetic hyperthermia (42-45 °C). The thermoresponsive behaviour of the p(MEO2MA-co- OEGMA)89:11 copolymer shown the better results to the purpose, presenting a lower critical solution temperature of around 42°C. The p(MEO2MA-co-OEGMA)89:11 copolymer could not be electrospun by itself. Therefore, two auxiliary polymers were used to evaluate the electrospinning abillity and to produce fibers with p(MEO2MA-co-OEGMA)89:11. Solutions of polyethylene oxide were prepared but the results of the electrospinning of a control fiberwere not adequate. Therefore, the choice of poly(vinyl alcohol) (10% (w/v)), whose electrospinning parameters were already optimized, was the best fit for the production of smart fibers using the thermoresponsive p(MEO2MA-co-OEGMA)89:11 copolymer. Lastly, after the optimization of electrospinning parameters, the electrospun nanofibers were characterized in terms of morphology to evaluate fiber diameter and homogeneity. PVA-p(MEO2MA-co-OEGMA)89:11 membranes with a ratio of 1:1 of PVA p(MEO2MA-co- OEGMA)89:11, respectively, and presented the most adequate results. PVA-p(MEO2MA-co-OEGMA)89:11 membranes presenting a lower critical solution temperature in the range of hyperthermic temperatures (42-45 °C) show, for this reason, potential to be used in alternative cancer treatment applications.