Programa de Pós-graduação em Genética e Biologia Molecular
URI Permanente desta comunidade
Navegar
Navegando Programa de Pós-graduação em Genética e Biologia Molecular por Por Orientador "Amaral, André Corrêa"
Agora exibindo 1 - 6 de 6
Resultados por página
Opções de Ordenação
Item Desenvolvimento e caracterização de nanopartículas mistas de quitosana e lecitina contendo melatonina para o tratamento de feridas em ratos diabéticos(Universidade Federal de Goiás, 2020-08-19) Corrêa, Viviane Lopes Rocha; Leite, Liliana Borges de Menezes; http://lattes.cnpq.br/2012543423092393; Amaral, André Corrêa; http://lattes.cnpq.br/8801299423520104; Amaral, André Corrêa; Bocca, Anamélia Lorenzetti; Tedesco, Antônio Cláudio; Diniz, Danielle Guimarães Almeida; Miguel, Marina PachecoWound healing in diabetic patients remains a worldwide problem that can cause amputations and even lead to death. This work aimed to produce melatonin-loaded lecithin-chitosan nanoparticles (MEL-NP) and to evaluate a topical formulation containing these particles for healing in an in vivo animal model for diabetes. For the production of nanoparticles, an ethanolic solution containing soybean lecithin and melatonin was dropwise added to an aqueous solution of chitosan under sonication. The nanoparticles were physical-chemical characterized and evaluated in vivo for toxicity using the Galleria mellonella model and its potential for wound healing in diabetic rats. The MEL-NP were around 160 nm in size and had a zeta potential around 25 mV. The melatonin entrapment efficiency was 27%. Our results demonstrated that treatment with MEL-NP improved wound healing demonstrated by a wound closure earlier than the other treatments evaluated. An appreciated therapeutic effect was achieved by MEL-NP in the induction of fibroblasts and angiogenic proliferation. In addition, it was accompanied by an expressive collagen deposition. Taking the observed data, the MEL-NP produced could be used in the development of promising strategies for wound healing in diabetic people.Item Produção da enzima ciclodextrina glicosiltransferase por Bacillus sp. imobilizados em quitosana(Universidade Federal de Goiás, 2015-02-20) Es, Ismail; Amaral, André Corrêa; http://lattes.cnpq.br/8801299423520104; Amaral, André CorrêaProduction of a starch-degrading cyclodextrin glicosiltransferase (CGTase, EC 2.4.1.19) on solid-state culture and batch fermentation was evaluated by free and immobilized alkalophilic Bacillus sp on polymeric chitosan matrix. Immobilization procedure was performed by mixing bacterial cells with low molecular weight chitosan dissolved in HCl. Structure of free bacterial cell, polymeric chitosan matrix and immobilized cells were visualized by scanning electron microscopy (SEM). The images obtained from SEM showed that the procedure used for immobilization was easy, cheap and effective. Three different starch sources as substrate were used: potato, corn and cassava. Qualitative analysis of CGTase production was determined by colorless area formation on solid culture containing phenolphthalein. Enzymatic indices, which indicated the production of CGTase on solid culture, were calculated for both free and immobilized cells on different starch sources. Enzyme activity of CGTase was determined before and after each purification step: ammonium sulfate precipitation, starch adsorption and dialysis. Biomass growth and substrate consumption were analyzed by Flow cytometry and modified phenol-sulfuric acid assay, respectively. Free cells reached very high numbers (2.5 × 107 ml-1) during batch culture, besides; immobilized cells maintained initial inoculum concentration (2.5 × 105 ml-1) during enzyme production. The maximum enzyme activity achieved by free cells was 21.25 U (35 h), 14.65 U (40 h) and 19.16 U (33 h) on cassava, potato and cornstarch, respectively. During batch culture, immobilized cells produced CGTase with the enzyme activity of 24.375 U (16 h) for cassava, 24.375 U (9 h) for potato starch and 21.25 U (8.5 h) for cornstarch in a shorter cultivation time. Consequently, immobilization decreased the production time and increased enzyme activity of CGTase.Item Desenvolvimento e testes in vivo de nanopartículas de quitosana contendo insulina na cicatrização de feridas em ratos diabéticos(Universidade Federal de Goiás, 2019-04-16) Ribeiro, Maycon Carvalho; Menezes, Liliana Borges de; http://lattes.cnpq.br/2012543423092393; Amaral, André Corrêa; http://lattes.cnpq.br/8801299423520104; Menezes, Liliana Borges de; Miguel, Marina Pacheco; Mendes, Elizabeth Pereira; Souza, Taís Andrade Dias de; Silva, Luís Antônio Dantas daChitosan has been studied for its ability to accelerate healing and has been tested in the therapy of difficult-to-heal lesions, such as in diabetic patients. Insulin acts by stimulating the signaling pathway for wound healing. The objective of this work was to produce chitosan nanoparticles containing insulin for the evaluation of cicatrizant activity in diabetic rats. For the formation of the nanoparticles, the ionic gelation method was used. The nanoparticles were analyzed by diameter, potential zeta polydispersity index. The degree of deacetylation of chitosan by potentiometric was determined. For the insulin- associated nanoparticles, the mean diameter was 245.9 ± 25.46 nm and zeta potential of 39.3 ± 4.88 mV and PDI of 0.463 ± 0.01. The mean degree of deacetylation found was 72.95%. The Bradford assay revealed that the nanoparticles incorporated 97.19% ± 2.18 of insulin. To evaluate the healing, 72 Wistar rats were divided in four groups: sepigel (S), sepigel with insulin (SI), empty chitosan nanoparticles (QV) and chitosan nanoparticles containing insulin (IQ). The groups were subdivided into three subgroups (n = 6) according to the histological analysis times of the wound (3rd, 7th and 14th day). The induction of diabetes occurred through the intraperitoneal application of alloxan (120mg / kg). After confirmation of the diabetes state, the animals were anesthetized and the wounds were made with an 8.0 mm punch in the dorsal region. Macroscopic and microscopic analyzes were performed. It was possible to produce chitosan nanoparticles by the ionic gelation method, with desired diameter and zeta potential and polydispersity index. No differences were found in the rate of wound retraction among the four groups. The topical use of empty or insulin-containing chitosan nanoparticles in wound healing in diabetic rats was able to stimulate inflammatory cell proliferation and angiogenesis, followed by wound maturation. Differences in wound healing data from the group treated with insulin-containing nanoparticles and from the group treated with free insulin may be related to the high stability of theItem Bioprospecção e caracterização de bactérias produtoras de ciclodextrina glicosiltranferase em solos de biomas brasileiros(Universidade Federal de Goiás, 2014-08-04) Ribeiro, Maycon Carvalho; Amaral, André Corrêa; http://lattes.cnpq.br/8801299423520104; Amaral, André Corrêa; Vieira, José Daniel Gonçalves; Fernandes, Éverton Kort KampCyclodextrin glycosyltransferase (CGTase, EC 2.4.1.19) is an important industrial enzyme for being the only one able to convert starch and related glucans in cyclic oligosaccharides called cyclodextrins (CDs). The arrangement of the glucose units in the formation of CD results in a molecule with the shape of a cone, with hydrophobic interior and hydrophilic surface. This arrangement of glucose molecules in CDs allows its use as a host molecule in the formation of inclusion complexes with organic and inorganic compounds. This mechanism is advantageous in protecting the guest molecule from light, heat and oxidizing conditions and also enable the "dissolution" of compounds of low solubility in aqueous media. Cyclodextrins are used from the food industry to the pharmaceutical, in controlled drug delivery systems and immobilization of toxic compounds for environmental protection. The CGTases are mainly produced by bacteria of the genus Bacillus, found degrading starch rich substrates. The aim of this study was to identify, isolate, select and characterize strains of CGTase-producing bacteria from soil samples from different regions of Brazil as well as calculate the enzymatic production of these bacteria on low-cost substrates. With this work, it was possible to identify 17 bacteria producing cyclodextrin glycosyltransferase enzyme, with nine of them had values above 1.5 for enzymatic production. Of these, all were characterized as gram positive Bacillus. Bioprospecting of bacteria in soils of different cultures led to the identification of bacteria that may be used in studies for the production of cyclodextrin glycosyltransferase and subsequent implementation by various industries.Item Produção de quitinase por paenibacillus illinoisensis imobilizados em matriz de alginato(Universidade Federal de Goiás, 2018-05-04) Silva, Francenya Kelley Lopes da; Amaral, André Corrêa; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4753997T1; Amaral, André Corrêa; Carneiro, Lilian Carla; Faria, Fabrícia Paula deChitins are enzymes that act in the hydrolysis of chitin, a polysaccharide present in insect exoskeletons, crustacean shells, algae and fungal cell walls. Such enzymes can be applied in the preparation of chitosan and chitoligomers for pharmaceutical use, in the control of pathogenic fungi and in the treatment of chitinous residues derived from fishing. Improvement in the production of chitinase and other enzymes by microorganisms can be achieved by the cell immobilization technique, which consists in fixing or confining cells in an inert carrier. The cell immobilization confers protection against the shear force, promotes the easy separation of the cells from the culture medium, as well as the product and decrease of the cost of production, since, it allows the reuse of the biocatalyst. Among the materials used as support in a cellular immobilization, biopolymers, such as alginate, have been highlighted as non-toxic, inexpensive and highly available in nature. The present work aims to immobilize Paenibacillus illinoisensis in a polymer matrix of alginate for chitinase production, evaluating the differences in the production of the enzyme between free and immobilized cells. Thus, an anionic alginate solution containing the cells was dripped into a cationic solution of CaCl2, leading to the instant formation of spheres having an average size of 4 mm. The immobilization efficiency was 99.99% ± 0.01. The biomass was determined during enzymatic production and the maximum values were 1.45 x 108 CFU / mL in 96 hours for immobilized cells and 8.95 x 107 CFU / mL in 48 hours for free cells, evidencing an increase of 62.01% in the amount of cells immobilized in comparation to the free cells. The cell leakage from the immobilization support during the process was evaluated and corresponded to 6.46% of the total cells at the end of the fermentation. The enzymatic activity was 0.902 U in 96 hours for the immobilized cells and 0.641 U in 48 hours for the free cells, demonstrating an activity increase of 40.71%. The immobilized cells were also tested for reuse in a sequential batch system and demonstrated stability in the production for 4 cycles of 96 hours each, losing 21.04% of the initial activity at the end of the fourth cycle. The cellular immobilization methodology resulted in spheres with capacity to maintain the cell viability during the bioprocess, increase of the enzymatic activity, low leakage of cells of the support and reuse capacity, being able to be used in the future for the production of chitinase for its various applications.Item Identificação e seleção de bactérias produtoras de quitinases(Universidade Federal de Goiás, 2016-04-29) Soares, Enio Saraiva; Amaral, André Corrêa; http://lattes.cnpq.br/8801299423520104; Amaral, André Corrêa; Vieira, José Daniel Gonçalves; Rodriguez, Armando GarciaCurrently there are different approaches to synthesize and discover new compounds, but the pursuit of these products on biodiversity is still advantageous. In bioprospecting microorganisms, which often are seeking their properties that can be exploited in biotechnology products. This is the case of chitinases, enzymes that degrade chitin. Chitinases (EC 3.2.1.29) are glycosyl hydrolases type enzymes that specifically cleave β-1,4 bonds between N-acetylglucosamines units of chitin with sizes ranging from 20 kDa to 90 kDa. The main producers of chitinase are the bodies that have chitin in their cell wall or exoskeleton, such as insects, crustaceans, fungi, algae, among others. This study aimed to select and identify producing bacteria chitinase in soil samples from different coastal regions of southern Brazil. Seventeen soil samples, collected close to fishing for shellfish waste disposal sites, were prepared and seeded in four minimum culture medium containing colloidal chitin as the sole source of carbon and energy, incubated and the colonies were isolated and purified. After yielded a total of thirteen isolates that were submitted to enzymatic index test, stressed that four isolates. The four isolated genomic DNA was extracted, amplified and purified, and sequenced region encoding 16S rRNA of these organisms. Bacteria were then pooled and identified by construction of a phylogenetic tree. The results showed the presence of the species Paenibacillus illinoisensis and Paenibacillus chitinolyticus and two members of the genus Bacillus. Future studies may indicate the possibility of its use as a source of genes for biotechnological applications such as the production of new biopesticides.