In this study, biopolymer-based pH-sensitive hydrogels have been successfully prepared using alginate, κ-carrageenan and pectin aimed at the encapsulation of pancreatin (hydrolytic enzymes like α-amylase, lipase and protease) so as to preserve enzymatic activities. Hydrogels have been characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), swelling degree and swelling profile. Encapsulation efficiency and in vitro studies on delayed release have also been evaluated. All hydrogels presented low swelling degree and enzyme release in a gastric medium. On the other hand, high swelling degree and enzyme release were observed in an intestinal medium. Alginate hydrogel achieved optimal results concerning encapsulation efficiency (18, 68 and 53% for α-amylase, lipase and protease, respectively) and delayed release (363, 7,673 and 17,497 U for α-amylase, lipase and protease, respectively) which has been afterwards compared to a commercial pancreatin formulation (CreonTM 10,000). Thus, it presented better performance than its commercial formulation, mainly in respect of lipase.

Lipase from Thermomyces lanuginosus was covalently immobilized on activated poly-hydroxybutyrate, sugarcane bagasse and the chemically modified hybrid hydrogel chitosan-alginate prepared by different strategies. Among the tested supports, chitosan-alginate chemically modified with 2,4,6-trinitrobenzenesulfonic acid rendered derivatives with the highest hydrolytic activity and thermal-stability, 45-fold more stable than soluble lipase and was then selected for further studies. The pH of maximum activity was similar for both immobilized and free lipase (pH 8.0) while optimum temperature was 5 - 10 ºC higher for the immobilized lipase. Higher yields in the butyl butyrate synthesis were found for the derivatives prepared by activation with glycidol and epichlorohydrin.

The aim of this work was to verify the ability of enzymatic crude extract from dormant castor bean seeds to yield concentrated fatty acids by hydrolysis of polyunsaturated vegetable oils such as corn and sunflower. The enzymatic extract exhibited higher activity towards corn oil, which was selected for further studies to determine optimum hydrolysis conditions by factorial design. Maximum hydrolysis percentage (≈84%) was reached at 60% wt. oil:buffer acetate 100 mM pH 4.5, 33 ºC and 5.0% wt. of crude extract after 70 min of reaction. These results suggest that the use of low-cost lipase from castor bean seeds has potential for oil hydrolysis.

FUNDAMENTO: A taxa de vasorreatividade pulmonar da Hipertensão Arterial Pulmonar Esquistossomótica (HAPE) não é conhecida. Dados hemodinâmicos obtidos pelo cateterismo cardíaco associam-se aos critérios clínicos de gravidade mais utilizados. OBJETIVO: Estimar o percentual de vasorreatividade positiva ao óxido nítrico em hipertensão arterial pulmonar esquistossomótica; verificar nesses pacientes a associação de parâmetros hemodinâmicos com a classificação funcional da OMS e teste de caminhada de seis minutos. MÉTODOS: Foram selecionados 84 pacientes portadores de hipertensão pulmonar de etiologia esquistossomótica de um banco de dados, submetidos ao cateterismo cardíaco direito e esquerdo com realização do teste de vasorreatividade pulmonar com óxido nítrico. Foram coletados os dados da classificação funcional da OMS e do teste de caminhada de seis minutos para fim de comparação com os dados invasivos. RESULTADOS: Dos 84 pacientes portadores de HAPE, três (3,5%) apresentaram os critérios para vasorreatividade pulmonar positivo. O aumento da resistência vascular pulmonar esteve associado significativamente à menor capacidade de esforço aferida pelo teste de caminhada de seis minutos (p = 0,045) e maiores sintomas de gravidade por meio de maiores classificações funcionais da OMS (classes III/IV) (p = 0,013). A diminuição da saturação de oxigênio na artéria pulmonar esteve associada significativamente a maiores classificações funcionais (p = 0,041). CONCLUSÃO: A taxa de resposta pulmonar ao teste de vasodilatação dos pacientes esquistossomóticos encontra-se abaixo dos valores encontrados para hipertensão pulmonar de etiologia idiopática. A resistência vascular pulmonar e a saturação de oxigênio na artéria pulmonar são dados hemodinâmicos que podem ser utilizados como marcadores de gravidade na hipertensão pulmonar esquistossomótica.

BACKGROUND: The pulmonary vasoreactivity rate of Schistosomal Pulmonary Artery Hypertension (SPAH) is not known. Hemodynamic data obtained by cardiac catheterization are associated with the most commonly used clinical criteria of severity. OBJECTIVE: To estimate the percentage of positive vasoreactivity to nitric oxide in schistosomal pulmonary arterial hypertension and verify the association of hemodynamic parameters with WHO functional classification and the six-minute walk test in these patients. METHODS: A total of 84 patients with schistosomal pulmonary hypertension were selected from a database, who had been submitted to the right and left cardiac catheterization and pulmonary vasoreactivity test with nitric oxide. Data on WHO functional classification and six-minute walk test were collected for comparison with invasive data. RESULTS: Of the 84 patients with SPAH, 3 (3.5%) had positive criteria for pulmonary vasoreactivity. The increase in pulmonary vascular resistance was significantly associated with lower exercise capacity measured by the six-minute walk test (p = 0.045) and greater symptom severity by higher functional classifications (WHO class III/IV) (p = 0.013). The decrease in oxygen saturation in the pulmonary artery was significantly associated with higher functional classifications (p = 0.041). CONCLUSION: The pulmonary response rate to the vasodilation test of schistosomiasis patients is below the values found for idiopathic pulmonary hypertension. Pulmonary vascular resistance and oxygen saturation in the pulmonary artery are hemodynamic data that can be used as markers of severity in schistosomal pulmonary hypertension.

Lipase from Candida rugosa was immobilized by covalent attachment on hybrid SiO2-chitosan obtained by sol-gel technique. A comparative study between free and immobilized lipase was provided in terms of pH, temperature, kinetic parameters and thermal stability on the olive oil hydrolysis. The pH and temperature for maximum activity shifted from 7.0 and 45 ºC for the free lipase to 7.5 and wide range of temperature (40-50 ºC) after immobilization. Kinetics parameters were found to obey Michaelis-Menten equation and K M values indicated that immobilization process reduced the affinity of enzyme-substrate; however Kd values revealed an increase of thermal stability of lipase.

Chitosan, poly[β-(1-4)-linked-2-amino-2-deoxy-D-glucose], is the N-deacetylated product of chitin which is a major component of arthropod and crustacean shells such as lobsters, crabs, shrimps, and cuttlefishes. In addition, chitosan has many significant biological and chemical properties such as biodegradability, biocompatibility and bioactivity as well as polycationic properties. Thus, it has been widely used in many industrial and biomedical applications including wastewater treatment, chromatographic support, carriers for controlled drug delivery and enzyme immobilization. This review is an insight into the exploitation of utilization of chitosan based-supports in different geometrical configurations on the immobilization of enzymes by different protocols for further application in biotransformation reactions.

The oleochemical industry has a permanent interested in controlling the physical, functional and organoleptical properties of their products and in producing useful derivatives from their raw materials. The potential of biotechnology for developing novel or well-known products at more competitive costs meets the need of this industrial segment in expanding their goals. In this work some technical aspects, problems and perspectives related to the production of oil and fat derivatives using biotransformation techniques are discussed. Particular emphasis is given to the description of biotransformation processes using lipase as catalyst, in view of the great versatility of this enzyme class to mediate typical reactions in this technological sector.