Programa de Pós-graduação em Biologia da Relação Parasito-Hospedeiro
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Navegando Programa de Pós-graduação em Biologia da Relação Parasito-Hospedeiro por Por Orientador "Amaral, André Corrêa"
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Item Nanopartículas poliméricas e interações com macrófagos(Universidade Federal de Goiás, 2016-09-16) Bandeira, Anielle Carvalho; Amaral, André Corrêa; http://lattes.cnpq.br/8801299423520104; Amaral, André Corrêa; Loyola, Patrícia Resende Alo Nagib; Celes, Mara Rúbia NunesNanotechnology involves the creation and use of materials, devices and systems through control of matter on the manometer scale. It has positive impact on medicine involving the treatment and diagnosis. Drug delivery systems prepared with nanostructures have the ability to overcome biological barriers and optimizing drug release. However, one of the main challenges in the use of these systems is their internalization by macrophages. This study aims to prepare and characterize polymer nanoparticles formed by biodegradable polymers and investigate its impact on the function of macrophages in vitro by the observation of cell viability, phagocytic activity and cytokine production. Also, was investigate the cytokine profile in serum and splenocytes culture supernatant from Balb/C mice injected with chitosan nanoparticles. The chitosan and chitosan-containing magnetic nanoparticles were prepared by ionic gelation crosslinking, resulting in a morphology "nearly spherical" and positive zeta potential. The PLGA prepared by emulsification and solvent evaporation method presented spherical morphology and negative zeta potential. All preparations had a diameter smaller than 300 nanometers and polydispersity index lower than 0.5. Nanoparticles of chitosan and PLGA affected the viability of macrophages in vitro only at the highest concentration tested (4 mg/mL). The chitosan nanoparticles containing magnetic nanoparticles were internalized by macrophages after 4h and 24h of incubation. Different nanoparticles triggered high production of TNF- and low IL12p40 production and IL-10. Serum and splenocytes culture supernatant was observed in both the production of IFN- as IL-4. However, IL-4 production was higher than that of IFN-.Item Quitinases humanas e infecções fúngicas(Universidade Federal de Goiás, 2023-02-27) Farias, Adriane Nunes; Amaral, André Corrêa; http://lattes.cnpq.br/8801299423520104; Amaral, André Corrêa; Silva, Daniela de Melo e; Soares, Renata de Bastos AscençoThis work deals with a systematic review of the intrinsic mechanisms used by humans to fight fungal infections, focusing on chitinases, discussing the main enzymes and gene polymorphism with them involved. Fungal infections are increasingly common in the world, being considered one of the main causes of death in immunocompromised and immunosuppressive patients. Diagnoses and treatments for these infections are still limited and prophylaxis through vaccines is still far from being achieved. Fungi, in general, have chitin in their cell wall, the second most abundant polymer in nature, not found in humans. However, enzymes capable of degrading it, called chitinases, are synthesized by them. Human chitinases are found in the family 18 of glycosyl hydrolases, of which only chitotriosidase (QT), mammalian acid chitinase (AMCase) and di-N-acetyl-chitobiase have chitinolytic activity. QT and AMCase are the most reported chitinases in humans and differ mainly in terms of the chitin cleavage region and the immune response that leads to their expression. The enzymatic activity of chitinases has been observed in several diseases, including fungal infections such as candidiasis, mycetoma and aspergillosis. It is believed that these enzymes act on the innate immune system against pathogenic fungi and their absence or inactivity leads to susceptibility to these organisms. Polymorphisms associated with genes encoding chitinases, especially QT, have been recently described. The duplication of 24 bp in exon 10 of the gene that expresses QT results in a protein with enzyme deficiency. Therefore, this review seeks to gather existing data on fungal infections, their relationship with chitinases, discussing the influence of gene polymorphisms on the chitinolytic activity of these enzymes against pathogenic fungi.Item Desenvolvimento de terapia alternativa usando adjuvantes nanoestruturados para o tratamento de tumor experimental(Universidade Federal de Goiás, 2016-04-08) Praxedes, Layanny Kelly Silveira; Silveira, Lucimeire Antonelli da Silveira; http://lattes.cnpq.br/1252319967725429; Amaral, André Corrêa; http://lattes.cnpq.br/8801299423520104; Silveira, Lucimeire Antonelli da; Fonseca, Simone Gonçalves da; Machado, Julianea ReisThe capacity of the tumor has not present as immunogenic to the immune system is one of its escape mechanisms. The aim of this study was to evaluate the use of nanoparticles formed from poly Lactic-co-glycolic acid (PLGA) associated with aluminum hydroxide may potentiate the effect of these on the resolution of the tumor. Balb/c mice inoculated with Sarcoma 180 tumor cells were distributed into nine groups for the implementation of the various immunotherapeutic treatments involving the use of aluminum hydroxide, PLGA nanoparticles, and activated macrophages. The evaluation of the treatment was performed by analysis of the tumor, considering the weight reduction of the dissected tumor, morphological and histological analysis, and analysis of pro-inflammatory and immunosuppressive cytokines in the serum of mice. The group of mice treated with PLGA nanoparticle associated with aluminum hydroxide caused a significant regression of the tumor (p = 0.039) compared with untreated mice. The treatment involving macrophages and PLGA nanoparticles showed significant tumor regression compared to the group treated only with macrophages (p = 0.021). The groups that had significant tumor regression have high levels of IFN--4 and IL-10, differing from the profile found in the other groups. In the other treatments tested there was a reduction of the tumor mass, but without significant statistical results, and without changes in the levels of cytokines measured in the serum of animals. Therefore, it is believed that PLGA nanoparticle by their ability to release hydroxide in target cells controlled manner, can enhance the action of the adjuvant aluminum hydroxide. Further studies are needed to elucidate the mechanisms involved in this phenomenon, which support the other investigationsItem Co-encapsulação do trans-cinamaldeído e do fluconazol em nanopartículas de quitosana para o tratamento tópico da candidíase vulvovaginal(Universidade Federal de Goiás, 2020-04-03) Sousa, Paulo Henrique Dantas de; Amaral, André Corrêa; http://lattes.cnpq.br/8801299423520104; Amaral, André Corrêa; Alves, Suzana Ferreira; Silva, Luís Antônio DantasVulvovaginal candidiasis is an infection caused by fungi of the genus Candida. The increased incidence of vulvovaginal candidiasis maybe related to the advancement of chronic and immunosuppressive diseases along with the emergence of new mechanisms of fungal resistance. The objective of the present work was to prepare and characterize chitosan nanoparticles containing fluconazole and trans-cinnamaldehyde co-encapsulated for the topical treatment of vulvovaginal candidiasis. The empty nanoparticles, fluconazole, trans-cinnamaldehyde and coencapsulated were prepared using the ionotropic gelling technique. The nanoparticles were characterized as to their average size and polydispersity index by the dynamic light scattering technique. The surface charge of the nanoparticles was obtained by the electrophoretic migration technique. The empty nanoparticles had an average size of 448,9 ± 32,9 nm, PdI of 0,4 ± 0,1 and a surface load of 31 ± 0,4 mV, the nanoparticles of fluconazole exhibited an average size of 175,3 ± 8,9 nm, PdI of 0,2 ± 0,01, surface load of 33,2 ± 0,3 mV and encapsulation efficiency of 37,5% ± 3,1. Trans-cinnamaldehyde nanoparticles showed an average size of 352,6 ± 71,6 nm, PdI of 0,4 ± 0,05, surface load of 44,6 ± 3,7 mV and encapsulation efficiency of 44,6 % ± 3,7 and the coencapsulated nanoparticles had an average size of 234,5 ± 60,2 nm, PdI of 0,4 ± 0,07, surface load of 33,2 ± 0,5 mV and encapsulation efficiency of 56,8% ± 3 for fluconazole and 46,1% ± 5,1 for trans-cinnamaldehyde. The scanning electron microscopy of the nanoparticles presented an oval shape. The nanoparticles had their antifungal efficacy against the strain of C. albicans ATCC 10231 investigated by means of the minimum inhibitory concentration by the broth microdilution technique. The fluconazole nanoparticle showed antifungal efficacy with a minimum inhibitory concentration of 2 μg/mL and the trans-cinnamaldehyde was effective in the concentration of 75 μg/mL. The coencapsulated nanoparticle exhibited a minimum inhibitory concentration of 2 μg/mL for fluconazole and 37,5 μg/mL for trans-cinnamaldehyde. The coencapsulated nanoparticle exhibited the same minimal inhibitory concentrations as the fluconazole and trans-cinnamaldehyde nanoparticles. As for in vitro toxicity, nanoparticles were considered non-toxic. Regarding the in vivo toxicity test, only the empty nanoparticles exhibited a cytotoxic effect. All groups of nanoparticles proved to be effective in inhibiting fungal growth.