60 documents found, page 1 of 6
The absence of albumin improves in vitro cellular uptake and disruption of Polo...
Loureiro, Ana Isabel Sá; Jennifer Noro; Abreu, Ana S.; Nogueira, E.; Soares da Costa, Diana; Silva, Carla; Cavaco-Paulo, ArturNovel nanoparticles based on Poloxamer 407 and vegetable oil were produced by high pressure homogenization. Functionalization of those nanoparticles was made by incorporation of folic acid (FA)-Poloxamer 407 conjugate. These nanoparticles showed suitable characteristics for intravenous therapeutic applications similarly to PEGylated albumin-based nanoparticles, previously described by our research group. Here, ...
High fluorescent water soluble CdTe quantum dots—a promising system for light h...
de Sá, Arsénio; Moura, Isabel; Abreu, Ana S.; Oliveira, Manuel António Sousa Cortez Gonçalves; Ferreira, Miguel F.; Machado, A. V.The entrapment of quantum dots (QDs) in the inner part of micelles formed by surfactant polymers is a powerful methodology to prepare stable and photoluminescent core nanoparticles with enhanced optical properties. These features are crucial for the application of QDs in the design of hybrid assemblies for light harvesting applications, where energy transfer processes are required. The present work was focused ...
Hybrid nanocomposites of a fluorescent block copolymer and quantum dots: an eff...
Moura, I.; de Sá, Arsénio; Abreu, Ana S.; Oliveira, M.; Machado, A. V.Forster resonance energy transfer (FRET) phenomenon has great potential in several applications, whose efficiency is dependent on the energy transfer between a suitable pair of fluorophores. In this work, a new block copolymer, PS-b-PS(co-pyren-1-yl), with fluorescent properties, was synthetized and used as donor component in the fluorophores pair copolymer/cadmium telluride quantum dots (CdTe QDs). Thus, water...
Polymeric materials for metal sorption from hydric resources
de Sa, Arsenio; Abreu, Ana S.; Moura, Isabel; Machado, A. V.Pure water is crucial for global population. However, a wide range of industrial activities contribute to its pollution. Among the pollutants, heavy metals are of high concern. Thus, it is crucial remove these pollutants from water for the population consumption. Several physical and chemical methods, such as chemical precipitation, filtration, coagulation, membrane processes, ion exchange, and adsorption are a...
Interaction of fluorescent quinolin-2-one and coumarin derivatives including di...
Abreu, Ana S.; Hermenegildo, Bruno Filipe Costa; Ferreira, Paula M. T.; Queiroz, Maria João R. P.; Castanheira, Elisabete M. S.The photophysical properties of two quinolin-2-one and two coumarin derivatives, a 3-amino-4-phenylquinolin-2-one 1, a N-(tert-butyloxycarbonyl)amino-4-phenylcoumarin 2, and the dipeptides 3 and 4 bearing the quinolin-2-one or the coumarin moiety, respectively, synthesized earlier by some of us, were studied in solvents of different polarity. Compounds 1 and 2 show a moderate solvent sensitive emission, quinoli...
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 ...
Morphology, optical, and electric properties of polymerquantum dots nanocomposi...
Moura, I.; de Sá, Arsénio; Abreu, Ana S.; Oliveira, M.; Machado, A. V.Polymer-CdTe quantum dots (QDs) nanocomposites were developed via solvent casting. Colloidal CdTe QDs, synthesized in aqueous solution, were transferred to organic media by exchanging of the original capping ligands by a long-chain thiol. Different commercial polymers (PMMA, OPS, PS, and PC), transparent in the visible spectral range, were chosen as matrices. Stock solutions of the polymers were prepared in sui...
Development of cellulose acetate membranes containing nanoparticles for water a...
Silva, Joana Luísa Padrão Cruz Costa e; Abreu, Ana S.; Oliveira, M.; Machado, A. V.The growth of human population and inherent activities, the improper industrialization practices, the direct addition of materials TO the waterway, and the excessive use of fertilizers containing phosphates to increase the production of crops are the main sources for the high input of phosphates in water bodies. These effects have been causing eutrophication, and bacterial contamination of the water. In fact, t...
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...
Size controlled protein nanoemulsions for active targeting of folate receptor p...
Loureiro, Ana Isabel Sá; Nogueira, Eugénia Sofia Costa; Azóia, Nuno G.; Sárria, M. P.; Abreu, Ana S.; Shimanovich, Ulyana; Rollett, AlexandraBovine Serum Albumin (BSA) nanoemulsions were produced by high pressure homogenization with a tri-block copolymer (Poloxamer 407), which presents a central hydrophobic chain of polyoxypropylene (PPO) and two identical lateral hydrophilic chains of polyethylene glycol (PEG). We observed a linear correlation between tri-block copolymer concentration and size - the use of 5 mg/mL of Poloxamer 407 yields nanoemulsi...