274 documents found, page 1 of 28
Ultrasound enhances lipase-catalyzed synthesis of poly (ethylene glutarate)
Xiaoman Zhao; Bansode, Sneha Ramrao; Ribeiro, Artur J.; Abreu, Ana S.; Oliveira, César; Parpot, Pier; Gogate, P. R.; Rathod, V. K.; Paulo, Artur CavacoThe present work explores the best conditions for the enzymatic synthesis of poly (ethylene glutarate) for the first time. The start-up materials are the liquids; diethyl glutarate and ethylene glycol diacetate, without the need of addition of extra solvent. The reactions are catalyzed by lipase B from Candida antarctica immobilized on glycidyl methacrylate-ter-divinylbenzene-ter-ethylene glycol dimethacrylate ...
Hydrophobic surface functionalization of lignocellulosic jute fabrics by enzyma...
Dong, Aixue; Fan, Xuerong; Wang, Qiang; Yu, Yuanyuan; Paulo, Artur CavacoEnzymatic grafting of synthetic molecules onto lignins provides a mild and eco-friendly alternative for the functionalization of lignocellulosic materials. In this study, laccase-mediated grafting of octadecylamine (OA) onto lignin-rich jute fabrics was investigated for enhancing the surface hydrophobicity. First, the lignins in jute fabrics were isolated and analyzed in the macromolecular level by MALDI-TOF MS...
Enzymatic synthesis of poly(catechin)-antibiotic conjugates: an antimicrobial a...
Gonçalves, Idalina; Abreu, Ana S.; Matamá, Maria Teresa; Ribeiro, Artur J.; Gomes, Andreia C; Silva, Carla Manuela Pereira Marinho daBiofilm formation in urinary indwelling catheters is one of the most critical issues that patients face. Catheters were coated with poly(catechin)-antibiotic conjugates with enhanced antimicrobial properties. Catechin was conjugated with two antibiotics, namely trimethoprim (TMP) and sulfamethoxazole (SMZ) via activation with N,N′-disuccinimidyl carbonate (DSC) and subsequent coupling to molecules containing α-...
HRP-mediated polyacrylamide graft modification of raw jute fabric
Liu, Ruirui; Dong, Aixue; Fan, Xuerong; Wang, Qiang; Yu, Yuanyuan; Paulo, Artur CavacoThe horseradish peroxidase (HRP)/hydrogen peroxide system can catalyze the free-radical polymerization of aromatic compounds such as lignins. In this study, to improve the hydrophilicity of lignin-rich jute fabrics, acrylamide (AM) was grafted onto their surface by HRP-mediated oxidative polymerization. The resulting AM-lignin graft polymer in jute fibers, from which the lignin was removed by extracting with di...
Stabilization of enzymes in micro-emulsions for ultrasound processes
Martins, Madalena A.; Azóia, Nuno G.; Silva, Carla Manuela Pereira Marinho da; Paulo, Artur CavacoOil-in-water proteinaceous micro-emulsions are described as novel methodology for the stabilization of enzymes. Proteins are tightly packed at the oil-water interface of micro-emulsions and it was found that micro-emulsions of laccases enzymes have enhanced stability under high temperatures and ultrasound fields (see graphical abstract scheme and data). This stabilization technique seems to be a promising metho...
Functionalized protein nanoemulsions by incorporation of chemically modified BSA
Loureiro, Ana; Abreu, Ana S.; Sárria, M. P.; Figueiredo, Mafalda C. O.; Saraiva, Lígia M.; Bernardes, Gonçalo J. L.; Gomes, Andreia CThe incorporation of bioactive compounds in stealth nanoparticles or nanoemulsions enhances their half-life in systemic circulation and can overcome the problems associated with the free drug. Bovine serum albumin (BSA)-drug conjugates were produced with either methotrexate (MTX), a potent anticancer agent, or vancomycin (VCM), a potent antibiotic. Those conjugates were used to produce functionalized BSA nanoem...
Improved Poly (D,L-lactide) nanoparticles-based formulation for hair follicle t...
Fernandes, Bruno Pacheco; Silva, R.; Ribeiro, Artur J.; Matamá, Maria Teresa; Gomes, Andreia C; Paulo, Artur CavacoObjective Hair follicles are widely recognized as the preferential target and site of accumulation for nanoparticles after topical application. This feature is of particular importance for hair cosmetics, having the potential to refine the treatment of several hair follicle-related disorders. The aim of this work was to improve the preparation of Poly (D,L-lactide) (PLA) nanoparticles for in vivo follicular tar...
Orange IV stabilizes silk fibroin microemulsions
Ferreira, A. V.; Volkov, Vadim; Abreu, Ana S.; Azóia, Nuno G.; Botelho, C. M.; Paulo, Artur CavacoSilk fibroin (SF) is a natural biopolymer that has been extensively studied in various applications due to its impressive mechanical properties and biocompatibility. Recently, SF-based particles have been proposed as controlled drug delivery systems. A new and efficient method to prepare SF microemulsions (SF-MEs) was developed by oil-in-water emulsions using high-pressure homogenization to promote emulsificati...
Phosphorylated silk fibroin matrix for methotrexate release
Volkov, Vadim; Sárria, M. P.; Gomes, Andreia C; Paulo, Artur CavacoSilk-based matrix was produced for delivery of a model anticancer drug, methotrexate (MTX). The calculation of net charge of silk fibroin and MTX was performed to better understand the electrostatic interactions during matrix formation upon casting. Silk fibroin films were cast at pH 7.2 and pH 3.5. Protein kinase A was used to prepare phosphorylated silk fibroin. The phosphorylation content of matrix was contr...
Ultrasound enhanced laccase applications
Gonçalves, Idalina; Silva, Carla Manuela Pereira Marinho da; Paulo, Artur CavacoLaccases (EC 1.10.3.2) are copper-containing enzymes that oxidize a variety of phenolics and other aromatic compounds through a radical-catalyzed mechanism. The use of mediators acting as vehicles for electron transfer can expand the range of laccase substrates to other classes of chemical compounds. Ultrasound irradiation through a liquid medium generates reactive free radical species, promoting a local turbul...