Encontrados 29 documentos, a visualizar página 1 de 3

Ordenado por Data

Functional biopolymer-based matrices for modulation of chronic wound enzyme act...

Francesko, Antonio; da Costa, Diana Soares; Reis, R. L.; Pashkuleva, I.; Tzanov, Tzanko

Collagen, collagen/hyaluronic acid (HA) and collagen/HA/chitosan (CS) sponges loaded with epigallocatechin gallate (EGCG), catechin (CAT) and gallic acid (GA) were developed and evaluated as active chronic wound dressings. Their physico-mechanical properties, biostability, biocompatibility and ability to inhibit in vitro myeloperoxidase (MPO) and collagenase—major enzymes related with the persistent inflammatio...


GAGs-thiolated chitosan assemblies for chronic wounds treatment : control of en...

Francesko, Antonio; Costa, Diana Soares da; Lisboa, P.; Reis, R. L.; Pashkuleva, I.; Tzanov, Tzanko

Multilayered polyelectrolyte coatings comprising thiolated chitosan (TC) and glycosaminoglycans (GAGs), chondroitin sulphate and hyaluronic acid, were built using a layer-by-layer approach. The surface activity of these coatings for binding and inhibition of enzymes related to chronic inflammation, such as collagenase and myeloperoxidase, was assessed. The build-up of five bi-layers of TC/GAGs onto gold surface...


Thiolated chitosan/glycosaminoglycans multilayered films : QCM-D study on the f...

Francesko, Antonio; Díaz-Blanco, Carlos; Lisboa, P.; Costa, Diana Soares da; Pashkuleva, I.; Reis, R. L.; Tzanov, Tzanko

Layer-by-layer technique is widely used to produce polyelectrolyte multilayered films for material surface functionalization. The technique simplicity coupled with the biological potential of biopolymers, e.g. polysaccharides, make such assemblies a suitable choice for many biomedical applications. In this study the formation of the films comprising of thiolated chitosan and glycosaminoglycans (GAGs) by alterna...


Protein disulphide isomerase-assisted functionalization of keratin-based matrices

Fernandes, Margarida M.; Gomes, A. C.; Vasconcelos, Andreia; Munteanu, Florentina-Daniela; Tzanov, Tzanko; Gonçalves, M. Sameiro T.; End, N.

In living systems, protein disulphide isomerase (PDI, EC 5.3.4.1) regulates the formation of new disulphide bonds in proteins (oxidase activity) and catalyzes the rearrangement of non-native disulphide bonds (isomerase activity), leading proteins towards their native configuration. In this study, PDI was used to attach cysteine-containing compounds (CCCs) onto hair, to enhance compound migration within hair fib...


Combined ultrasound-laccase assisted bleaching of cotton

Basto, Carlos; Tzanov, Tzanko; Paulo, Artur Cavaco

This study evaluates the potential of using ultrasound to enhance the bleaching efficiency of laccase enzyme on cotton fabrics. Ultrasound of low intensity (7 W) and relatively short reaction time (30 min) seems to act in a synergistic way with the enzyme in the oxidation/removal of the natural colouring matter of cotton. The increased bleaching effect could be attributed to improved diffusion of the enzyme fro...


Environmentally friendly bleaching of cotton using laccases

Pereira, Luciana; Bastos, C.; Tzanov, Tzanko; Paulo, Artur Cavaco; Gübitz, Georg M.

A new strain of Trametes hirsuta was found to oxidize various cotton flavonoids. Here we show that laccases of this organism were responsible for oxidation of the flavonoids morin, luteolin, rutin and quercetin. Out of two laccases produced by T. hirsuta (60.7 and 51.0 kDa) the more prominent 60.7 kDa laccase was purified and showed Km and kcat values of 75.5, 20.9 and 49.4 μM and 72.5, 96.3 and 32.7 s−1, hours...


Predicting dye biodegradation from redox potentials

Zille, Andrea; Ramalho, Patrícia A.; Tzanov, Tzanko; Millward, Roy; Aires, Veronika; Cardoso, M. Helena; Ramalho, Maria Teresa; Gübitz, Georg M.

Two biological approaches for decolorization of azo sulfonated dyes have been compared: reductive decolorization with the ascomycete yeast Issatchenkia occidentalis and nzymatic oxidative decolorization with Trametes villosa laccase alone or in the presence of the mediator 1-hydroxybenzotriazole. The redox potential difference between the biological cofactor involved in the reductive activity of growing cells ...


Immobilized laccase for decolourization of Reactive Black 5 dyeing effluent

Zille, Andrea; Tzanov, Tzanko; Gübitz, Georg M.; Paulo, Artur Cavaco


Proteases to improve the mechanical characteristics of durable press finished c...

Stamenova, Maria; Tzanov, Tzanko; Betcheva, Rossica; Paulo, Artur Cavaco

N-Methylol reagents are conventional crosslinking agents that are still widely used in textile industry to produce crease-resistant cotton fabrics. In this work serine proteases were used to recover the strength of fabrics, crosslinked with N-hydroxymethylacrylamide. Nearly one half of the strength loss of rosslinked cotton fabrics could be restored after protease treatment, while the wrinkle recovery angle (W...


Effect of some pocess parameters in enzymatic dyeing of wool

Tzanov, Tzanko; Silva, Carla J. S. M.; Zille, Andrea; Oliveira, M. J.; Paulo, Artur Cavaco

This article reports on the dyeing of wool using an enzymatic system comprising laccase; dye precursor, 2,5- iaminobenzenesulfonic acid; and dye modifiers, catechol and resorcinol. Enzymatic dyeing was performed as a batchwise process at the temperature and pH of maximum enzyme activity. The effects of the process variables reaction time, enzyme, and modifier concentration on fabric color were studied, accordin...


29 Resultados

Texto Pesquisado

Refinar resultados

Autor











Data











Tipo de Documento



Recurso


Assunto















    Financiadores do RCAAP

Fundação para a Ciência e a Tecnologia Universidade do Minho   Governo Português Ministério da Educação e Ciência Programa Operacional da Sociedade do Conhecimento União Europeia