Magnetic bioactive glass-based fibrous system for bone cancer treatment

• Autor(a) principal: Correia, Beatriz Gomes
• Data de Publicação: 2021
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/160349
• topic: Bioactive glass; electrospinning; Magnetic hyperthermia; magnetic nanoparticles; poly- caprolactone; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia dos Materiais

Cancer is a global disease with growing incidence and related deaths. Only in 2020, almost 20 million new cases of cancer were diagnosed worldwide (Globocan 2020). Conventional cancer treat- ments such as chemotherapy and radiotherapy are not specific to cancer cells, causing severe side effects. Additionally, in some cases these treatments are ineffective in fighting the disease. Currently, a lot of research is being done for new therapeutic options for cancer, particularly in the development of multifunctional composite materials. This work focuses on the development of a composite system with magnetic nanoparticles (mNPs) and bioactive glass (BG) incorporated in electrospun polymer fi- bers for cancer treatment through magnetic hyperthermia application. Firstly, the electrospinning parameters were optimized to produce polycaprolactone (PCL) nano- fibers with monodisperse diameters and without defects. The average diameter of the optimized fibers was about 590 nm. Iron oxide nanoparticles were synthesized using the chemical precipitation method and stabilized with oleic acid (OA). These mNPs were incorporated in PCL fibers during electrospinning. BG was adsorbed at fiber surface using the dip coating method. X-ray diffraction and Fourier transform infrared spectroscopy results confirmed the presence of PCL, mNPs and BG in the composite membranes. Swelling and degradation tests were carried out, demonstrating that PCL membranes and PCL/mNPs membranes did not undergo swelling or degrada- tion in the studied conditions. However, composite membranes with BG initially swelled, but after 5 hours immersed in PBS (phosphate buffer solution) suffered a high degradation. This degradation is probably related to acid hydrolysis of PCL fibers when immersed in BG sol-gel. The incorporation of mNPs and BG in PCL membranes increased their rigidity but decreased their deformation capacity at the breaking point. Bioactivity is not affected by the incorporation of mNPs into PCL but cytotoxicity tests revealed a moderate toxicity in high concentrations of the extract. Finally, magnetic hyperthermia studies showed a temperature variation of the composite membrane of about 5.8 ºC, demonstrating the suitability of these composite membranes for magnetic hyperthermia applications.