OBTENÇÃO E CARACTERIZAÇÃO DE NANOPARTÍCULAS DE PLGA PARA VEICULAÇÃO INTRAVENOSA DE PROTEÍNAS

O desenvolvimento de nanopartículas é considerado atualmente um sistema promissor para o carreamento de drogas em sítios específicos. O uso de polímeros na obtenção desse sistema pode ser de origem natural ou sintética desde que seja biocompatível ou biodegradável. Desenvolver sistemas de transportes para carrear proteínas requer cuidado com variáveis como tempo de homogeneização e concentração do surfactante, que interferem diretamente na obtenção destas. As nanopartículas foram obtidas pelo método de dupla emulsificação, onde foram elaborados 6 sistemas (A,B,C,D,E e F), utilizando diferentes concentrações de PVA (0,5; 1 e 1,5%) e tempo de homogeneização de 30 e 60 segundos. Os sistemas foram analisados pela técnica de espalhamento de luz dinâmico. Os resultados mostraram que o sistema D apresentou melhor IPD com 0,638, com tamanho de partícula de 678,3 nm, o que sugere homogeneidade maior em relação aos outros sistemas. Porém, há a necessidade de se otimizar o método para obtenção de partículas de tamanhos menores para a veiculação intravenosa

Behavior of Triton X-114 cloud point in the presence of inorganic electrolytes

Nonionic surfactants display different behaviors in aqueous solution, depending on their concentration and the presence of small amounts of salts and/or ionic surfactants. Here, cloud point values of the aqueous two-phase micellar system formed by the nonionic surfactant Triton X-114 were determined in water and in McIlvaine buffer (pH 6.5), either in the presence or absence of various salts at different concentrations. The presence of salts lowered the cloud point values according to the sequence: 0.25 M MgSO4.7H2O > 0.5 M NaCl > 0.05 M MgSO4.7H2O 48 0.5 M CaCl2.2H2O 48 0.1 M NaCl > 0.1 M CaCl2.2H2O. These results demonstrate that the presence of electrolytes influences the cloud point of Triton X-114 system and that knowledge of this parameter is paramount before starting partitioning studies

Stability of clavulanic acid under variable pH, ionic strength and temperature conditions. A new kinetic approach

The main objective of this study was the evaluation of CA long-term stability under different conditions of pH and temperature, in the presence of variable levels of different salts, so as to suggest the best conditions to perform its simultaneous production and recovery by two-phase polymer/salt liquid\u2013liquid extractive fermentation

Production of extracellular l-asparaginase: from bioprospecting to the engineering of an antileukemic biopharmaceutical

L-asparaginase is an enzyme clinically accepted as an anti-tumor agent for the treatment of acute lymphoblastic leukemia and lymphosarcoma. The main focus of this study is to provide a thorough overview on microbial production of such a biopharmaceutical

Production of extracellular L-asparaginase: from bioprospecting to the engineering of an antileukemic biopharmaceutical

The L-asparaginase (L-asparagine amino hydrolase, E.C.3.5.1.1) catalyzes the hydrolysis of L-aspargine into L-aspartic acid and ammonia. The effective depletion of L-asparine results in cytotoxicity for leukemic cell. Therefore the enzyme has been a clinically acceptable anti-tumour agent for the effective treatment of acute lymphoblastic leukemia (ALL) and lymphosarcoma. L-asparaginase production using microbial system had attracted considerable attention, owing to the cost effective and eco friendly nature. A wide range of microorganisms such as filamentous fungi, yeasts and bacteria have proved to be the good sources of the enzyme L-asparaginase. Thus, in this review mainly focuses on the biochemical aspects of L-asparaginase production, aiming to comprehend the physiochemical characteristics, such as stability, bioavailability, toxicity, allergenic aspects, application, and enzyme properties and kinetics of recombinant enzyme production by fermentation. Processes central to these biochemical aspects, including fermentation of L-asparaginase producing organisms and downstream processing of the enzyme are also discusse