Estudo do processo de síntese dos dímeros lactídeo e glicolídeo para obtenção do PLGA Poli (Ácido Lático-co-Ácido Glicólico) utilizados na produção de fontes radioativas

Content Provider	Semantic Scholar
Author	Souza, Raquel Valério De
Copyright Year	2017
Abstract	Cancer is the second leading cause of world death and it was responsible for 8.8 million deaths in 2015, according to the World Health Organization (WHO). According to the National Cancer Institute (INCA), this disease is a public utility problem. In absolute values, prostate cancer, the most common cancer among men, is the sixth most common type in the world. Among prostate cancer treatments are surgery, chemotherapy and radiotherapy. One of the main radiotherapy types is brachytherapy, performed by iodine-125 radioactive seeds, which are inserted into the patient's prostate and release small radiation doses. These seeds can be introduced loose or such as stranded seeds. When introduced such as loose seeds, according to literature, these seeds can migrate to other organs. In order to avoid this migration, it is used stranded seeds. The stranded seeds are composed of PLGA, poly(lactic acid-co-glycolic acid). PLGA can be obtained by its cyclic dimers: glycolide and lactide. These dimers can be produced from their respective monomers, glycolic and lactic acids. The purpose of this study was to analyze and discuss the favorable conditions of the glycolide and lactide synthesis, such as process steps and temperature and pressure values. Seven experiments were performed at different temperatures and pressures in three synthesis steps: acid dehydration, prepolymer formation and depolymerization of prepolymer. In intermediary step, the PLA was obtained when temperatures were above 150oC. The final step showed that dimers are not formed at temperatures below 200oC.
File Format	PDF HTM / HTML
DOI	10.11606/D.85.2017.tde-05122017-155143
Alternate Webpage(s)	https://teses.usp.br/teses/disponiveis/85/85131/tde-05122017-155143/publico/2017SouzaEstudo.pdf
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article