@article{Almeida2013, abstract = {Experimental data on the surface tension and refractive index of tetradecyltrihexylphosphonium-based ionic liquids with bromide, chloride, decanoate, methanesulfonate, dicyanimide, bis(2,4,4-trimethylpentyl)phosphinate and bis(trifluoromethylsulfonyl)imide anions are reported. The data were obtained for pure and water saturated samples at temperatures from 283 K to 353 K and at atmospheric pressure. The refractive index of the investigated ionic liquids decreases with increasing the water content in the sample. On the other hand, no clearly dependence of the surface tension with the water content up to a weight fraction of 16% was found. The prediction of the refractive index for the studied ionic liquids was also accomplished by a group contribution method and new values for the cation and diverse anions were estimated and proposed. The studied ionic liquids show lower surface tension in comparison with imidazolium-, pyridinium- or pyrrolidinium-based ionic liquids with a similar anion; also they show higher surface entropy than cyclic nitrogen-based fluids which indicates a lower surface organization. The anion dependence of the surface tension and surface entropy for the investigated ionic liquids is weaker than that for short-chain imidazolium-based ionic liquids. Their critical temperatures evaluated from Eötvos and Guggenheim equations are also lower than those of N-heterocyclic ionic fluids.}, author = {Almeida, Hugo F. D. and Lopes da Silva, José A. and Freire, Mara G. and Coutinho, João A. P.}, doi = {10.1016/j.jct.2012.09.004}, journal = {Journal of Chemical Thermodynamics}, month = {feb}, pages = {372-379}, title = {Surface tension and refractive index of pure and water-saturated tetradecyltrihexylphosphonium-based ionic liquids}, url = {https://www.researchgate.net/profile/Joao_Coutinho/publication/256739002_Surface_tension_and_refractive_index_of_pure_and_water-saturated_tetradecyltrihexylphosphonium-based_ionic_liquids/links/55b8cc0308ae092e965a79e8.pdf}, volume = {57}, year = {2013} } @article{Almeida2014, abstract = {Aiming at providing a comprehensive study of the influence of the cation symmetry and alkyl side chain length on the surface tension and surface organization of ionic liquids (ILs), this work addresses the experimental measurements of the surface tension of two extended series of ILs, namely R,R′-dialkylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([CnCnim][NTf2]) and R-alkyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([CnC1im][NTf2]), and their dependence with temperature (from 298 to 343 K). For both series of ILs the surface tension decreases with an increase in the cation side alkyl chain length up to aliphatic chains no longer than hexyl, here labeled as critical alkyl chain length (CACL). For ILs with aliphatic moieties longer than CACL the surface tension displays an almost constant value up to [C12C12im][NTf2] or [C16C1im][NTf2]. These constant values further converge to the surface tension of long chain n-alkanes, indicating that, for sufficiently long alkyl side chains, the surface ordering is strongly dominated by the aliphatic tails present in the IL. The enthalpies and entropies of surface were also derived and the critical temperatures were estimated from the experimental data. The trend of the derived thermodynamic properties highlights the effect of the structural organization of the IL at the surface with visible trend shifts occurring at a well-defined CACL in both symmetric and asymmetric series of ILs. Finally, the structure of a long-alkyl side chain IL at the vacuum-liquid interface was also explored using Molecular Dynamics simulations. In general, it was found that for the symmetric series of ILs, at the outermost polar layers, more cations point one of their aliphatic tails outward and the other inward, relative to the surface, than cations pointing both tails outward. The number of the former, while being the preferred conformation, exceeds the latter by around 75%.}, author = {Almeida, Hugo F. D. and Freire, Mara G. and Fernandes, Ana M. and Lopes da Silva, José A. and Morgado, Pedro and Shimizu, Karina and Filipe, Eduardo J. M. and Canongia Lopes, José N. and Santos, Luís M. N. B. F. and Coutinho, João A. P.}, doi = {10.1021/la501308q}, journal = {Langmuir}, month = {may}, pages = {6408-6418}, title = {Cation Alkyl Side Chain Length and Symmetry Effects on the Surface Tension of Ionic Liquids}, url = {https://www.researchgate.net/profile/Joao_Coutinho/publication/278323158_Cation_Alkyl_Side_Chain_Length_and_Symmetry_Effects_on_the_Surface_Tension_of_Ionic_Liquids/links/55b8cb2808aec0e5f43b7955.pdf}, volume = {30}, year = {2014} } @article{Almeida2015, abstract = {Ionic liquids (ILs) with cyano-functionalized anions are a set of fluids that are still poorly characterized despite their remarkably low viscosities and potential applications. Aiming at providing a comprehensive study on the influence of the number of -CN groups through the surface tension and surface organization of ILs, the surface tensions of imidazolium-based ILs with cyano-functionalized anions were determined at atmospheric pressure and in the (298.15-343.15) K temperature range. The ILs investigated are based on 1-alkyl-3-methylimidazolium cations (alkyl = ethyl, butyl and hexyl) combined with the [SCN]-, [N(CN)2]-, [C(CN)3]- and [B(CN)4]- anions. Although the well-known trend regarding the surface tension decrease with the increase of the size of the aliphatic moiety at the cation was observed, the order obtained for the anions is more intricate. For a common cation and at a given temperature, the surface tension decreases according to: [N(CN)2]- > [SCN]- > [C(CN)3]- > [B(CN)4]-. Therefore, the surface tension of this homologous series does not decrease with the increase of the number of -CN groups at the anion as has been previously shown by studies performed with a more limited matrix of ILs. A maximum in the surface tension and critical temperature was observed for [N(CN)2]-based ILs. Furthermore, a minimum in the surface entropy, indicative of a highly structured surface, was found for the same class of ILs. All these evidences seem to be a result of stronger hydrogen-bonding interactions occurring in [N(CN)2]-based ILs, when compared with the remaining CN-based counterparts, and as sustained by cation-anion interaction energies derived from the Conductor Like Screening Model for Real Solvents (COSMO-RS).}, author = {Almeida, Hugo F. D. and Carvalho, Pedro J. and Kurnia, Kiki A. and Lopes da Silva, José A. and Coutinho, João A. P. and Freire, Mara G.}, doi = {10.1016/j.fluid.2015.10.044}, journal = {Fluid Phase Equilibria}, month = {nov}, pages = {458-465}, title = {Surface Tensions of Ionic Liquids: Non-Regular Trend Along the Number of Cyano Groups}, url = {http://europepmc.org/articles/pmc5024756?pdf=render}, volume = {409}, year = {2015} } @misc{Almeida2015_2, author = {Almeida, Hugo F. D. and Carvalho, Pedro J. and Kurnia, Kiki A. and Lopes da Silva, José A. and Coutinho, João A. P. and Freire, Mara G.}, month = {nov}, title = {j.fluid.2015.10.044 SI}, url = {https://www.researchgate.net/profile/Pedro_Carvalho9/publication/284183943_jfluid201510044_SI/links/564f0f0108aeafc2aab38c6b.pdf}, year = {2015} } @article{Almeida2016, author = {Almeida, Nuno A. and Martins, Pedro M. and Teixeira, Sara and Lopes da Silva, José A. and Sencadas, Vitor and Kühn, K. and Cuniberti, G. and Lanceros-Mendez, S. and Marques, Paula A. A. P.}, doi = {10.1007/s10853-016-9986-4}, journal = {Journal of Materials Science}, month = {apr}, pages = {6974-6986}, title = {TiO2/graphene oxide immobilized in P(VDF-TrFE) electrospun membranes with enhanced visible-light-induced photocatalytic performance}, url = {https://oadoi.org/10.1007/s10853-016-9986-4}, volume = {51}, year = {2016} } @article{Bhattacharjee2014, abstract = {Experimental data for the density, viscosity, refractive index, and surface tension of four sulfonium- and ammonium-based ionic liquids (ILs) with the common bis(trifluoromethylsulfonyl)imide anion were measured in the temperature range between 288.15 and 353.15 K and at atmospheric pressure. The ILs considered include butyltrimethylammonium bis(trifluoromethylsulfonyl)imide, [N4111][NTf2], tributylmethylammonium bis(trifluoromethylsulfonyl)imide, [N4441][NTf2], diethylmethylsulfonium bis(trifluoromethylsulfonyl)imide, [S221][NTf2], and triethylsulfonium bis(trifluoromethylsulfonyl)imide, [S222][NTf2]. Based on the gathered results and on data taken from literature, the impact of the cation isomerism and of the size of the aliphatic tails, as well as the effect resulting from the substitution of a nitrogen by a sulfur atom as the cation central atom, on the thermophysical properties of sulfonium- and ammonium-based ILs is discussed here. Remarkably, more symmetric cations present a lower viscosity for the same, and sometimes even for higher, alkyl chain lengths at the cation. Additional derivative properties, such as the isobaric thermal expansion coefficient, the surface thermodynamic properties and the critical temperature for the investigated ILs were also estimated and are presented and discussed.}, author = {Bhattacharjee, Arijit and Luís, Andreia and Santos, João H. and Lopes-Da-Silva, José A. and Freire, Mara G. and Carvalho, Pedro J. and Coutinho, João A. P.}, doi = {10.1016/j.fluid.2014.08.005}, journal = {Fluid Phase Equilibria}, month = {nov}, pages = {36-45}, title = {Thermophysical properties of sulfonium- and ammonium-based ionic liquids}, url = {http://www.ncbi.nlm.nih.gov/pubmed/25516634}, volume = {381}, year = {2014} } @article{Bhattacharjee2015, abstract = {Experimental data for density, viscosity, refractive index and surface tension of four phosphonium-based ionic liquids were measured in the temperature range between (288.15 and 353.15) K and at atmospheric pressure. The ionic liquids considered include tri(isobutyl) methylphosphonium tosylate, [Pi(444) 1][Tos], tri(butyl) methylphosphonium methylsulfate, [P4441][CH3SO4], tri(butyl) ethylphosphonium diethylphosphate, [P4442][(C2H5O)2PO2], and tetraoctylphosphonium bromide, [P8888][Br]. Additionally, derivative properties, such as the isobaric thermal expansion coefficient, the surface thermodynamic properties and the critical temperatures for the investigated ionic liquids were also estimated and are presented and discussed. Group contribution methods were evaluated and fitted to the density, viscosity and refractive index experimental data.}, author = {Bhattacharjee, Arijit and Lopes da Silva, José A. and Freire, Mara G. and Coutinho, João A. P. and Carvalho, Pedro J.}, doi = {10.1016/j.fluid.2015.05.009}, journal = {Fluid Phase Equilibria}, month = {may}, pages = {103-113}, title = {Thermophysical properties of phosphonium-based ionic liquids}, url = {http://europepmc.org/articles/pmc4591467?pdf=render}, volume = {400}, year = {2015} } @article{Lourenço2016, abstract = {AbstractExtracellular matrix (ECM) proteins play a key role during oligodendrogenesis. While fibronectin (FN) is involved in the maintenance and proliferation of oligodendrocyte progenitor cells (OPCs), merosin (MN) promotes differentiation into oligodendrocytes (OLs). Mechanical properties of the ECM also seem to affect OL differentiation, hence this study aimed to clarify the impact of combined biophysical and biochemical elements during oligodendrocyte differentiation and maturation using synthetic elastic polymeric ECM-like substrates. CG-4 cells presented OPC- or OL-like morphology in response to brain-compliant substrates functionalised with FN or MN, respectively. The expression of the differentiation and maturation markers myelin basic protein — MBP — and proteolipid protein — PLP — (respectively) by primary rat oligodendrocytes was enhanced in presence of MN, but only on brain-compliant conditions, considering the distribution (MBP) or amount (PLP) of the protein. It was also observed that maturation of OLs was attained earlier (by assessing PLP expression) by cells differentiated on MN-functionalised brain-compliant substrates than on standard culture conditions. Moreover, the combination of MN and substrate compliance enhanced the maturation and morphological complexity of OLs. Considering the distinct degrees of stiffness tested ranging within those of the central nervous system, our results indicate that 6.5 kPa is the most suitable rigidity for oligodendrocyte differentiation.}, author = {Lourenço, Tania and de Faria, Joana Paes and Paes de Faria, Joana and Bippes, Christian A. and Maia, João and Lopes da Silva, José A. and Relvas, João B. and Grãos, Mário}, doi = {10.1038/srep21563}, journal = {Scientific Reports}, month = {feb}, title = {Modulation of oligodendrocyte differentiation and maturation by combined biochemical and mechanical cues}, url = {https://www.nature.com/articles/srep21563.pdf}, volume = {6}, year = {2016} } @article{Luís2016, author = {Luís, Andreia and Shimizu, Karina and Araújo, João M. M. and Carvalho, Pedro J. and Lopes-Da-Silva, José A. and Canongia Lopes, José N. and Rebelo, Luís Paulo N. and Coutinho, João A. P. and Freire, Mara G. and Pereiro, Ana B.}, doi = {10.1021/acs.langmuir.6b00209}, journal = {Langmuir}, month = {jun}, pages = {6130-6139}, title = {Influence of Nanosegregation on the Surface Tension of Fluorinated Ionic Liquids}, url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5325320}, volume = {32}, year = {2016} } @article{Martins2015, abstract = {Determination of material properties and functions is a crucial step towards optimization of fabrication methods as well as the development of electrospun nanofibers for use in e.g. food engineering applications. This work focused in evaluating physical and mass transfer properties of simple poly -caprolactone nanofibers (PCL membrane), and poly ε-caprolactone nanofibers with encapsulated trypsin (E-PCL membrane), in view of their future use in a catalytic filter reactor. PCL membranes registered high hydrophobicity values, while E-PCL membranes revealed stronger mechanical properties and an increase of mass due to water incorporation. A decrease of average pore size in the range of 30% to 40% was observed for E-PCL membranes and an average pore diameter of 1/3 of the size was registered when compared to the PCL membrane; this difference was shown to be significant enough to influence the transport of larger molecules (e.g. bovine serum albumin). Release experiments of active compounds (lysozyme, bovine serum albumin and lactoferrin) were successfully described by a model which accounts for both Fick and Case II transport the linear superimposition model. Results show that the transport mechanism is influenced by the type of active compound and by membranes physical properties. ; The present study was developed under the scope of the NanoBioCats project (PTDC/CTM-POL/112289/2009), funded by the Portuguese Science and Technology Foundation (Fundação para a Ciência e a Tecnologia – FCT). This work was also supported by the COMPETE program (funded by the European Union fund, FEDER under the framework of QREN (Programa Operacional Regional do Norte (ON.2 – O Novo Norte; FEDER))) through projects NORTE-07-0124-FEDER-000028 and NORTE-07-0124-FEDER-000069. Also, the authors thank Strategic Projects PEst-OE/EQB/LA0023/2013, PEst-C/EQB/LA0006/2013 – FCOMP-01-0124-FEDER-37285 and PEst-C/QUI/UI0062/2013 – FCOMP-01-0124-FEDER-037296. The Fundação para a Ciência e Tecnologia (FCT, Portugal) through grant SFRH/BD/73178/2010}, author = {Martins, Artur J. and Bourbon, Ana I. and Vicente, António A. and Pinto, Susana and Lopes da Silva, José A. and Silva, José Lopes A. and Rocha, Cristina M. R.}, doi = {10.1016/j.procbio.2015.03.017}, journal = {Process Biochemistry}, month = {may}, pages = {885-892}, title = {Physical and mass transfer properties of electrospun ε-polycaprolactone nanofiber membranes}, url = {https://www.researchgate.net/profile/Artur_Martins3/publication/274891797_Physical_and_mass_transfer_properties_of_electrospun_e-polycaprolactone_nanofiber_membranes/links/567eabe108ae19758389860f.pdf}, volume = {50}, year = {2015} } @article{Maximo2013, abstract = {Protic ionic liquids (PILs) based on lipidic compounds have a range of industrial applications, revealing the potential of oil chemistry as a sustainable basis for the synthesis of ionic liquids. PILs of fatty acids with ethanolamines are here disclosed to form ionic liquid crystals, and their mixtures with the parent fatty acids and ethanolamines display a lyotropic behavior. Aiming at characterizing their rheologic and phase behavior, four ethanolamine carboxylates and the mixtures used for their synthesis through a Brønsted acid–base reaction are investigated. Their phase diagrams present a complex multiphase profile, exhibiting lyotropic mesophases as well as solid–liquid biphasic domains with a congruent melting behavior. These PILs present a high self-assembling ability and a non-Newtonian behavior with yield stress in the liquid crystal mesophase. The appearance of lamellar and hexagonal structures, with probably normal and inverted configurations in the mixtures, due to the formation of the PILs is responsible for the high viscoelasticity and notable nonideality that is mainly ruled by hydrophobic/hydrophilic interactions. Considering their renewable origin, the formation of liquid crystalline structures, in addition to the non-Newtonian behavior and ionic liquids properties, and the mixtures here evaluated possess a great potential, and numerous applications may be foreseen.}, author = {Maximo, Guilherme J. and Santos, Ricardo J. B. N. and Lopes-Da-Silva, José A. and Costa, Mariana C. and Meirelles, Antonio J. A. and Coutinho, João A. P.}, doi = {10.1021/sc400365h}, journal = {ACS Sustainable Chemistry and Engineering}, month = {dec}, pages = {672-682}, title = {Lipidic Protic Ionic Liquid Crystals}, url = {https://doi.org/10.1021/sc400365h}, volume = {2}, year = {2013} } @article{Monteiro2013, author = {Monteiro, Sónia R. and Rebelo, Sandra and da Cruz e. Silva, Odete A. B. and Lopes-Da-Silva, José A.}, doi = {10.1016/j.foodhyd.2013.04.012}, journal = {Food Hydrocolloids}, month = {dec}, pages = {349-360}, title = {The influence of galactomannans with different amount of galactose side chains on the gelation of soy proteins at neutral pH}, url = {https://oadoi.org/10.1016/j.foodhyd.2013.04.012}, volume = {33}, year = {2013} } @article{Nunes2016, abstract = {A novel approach is described using chitosan–genipin films as a sustainable method for wine preservation.}, author = {Nunes, Cláudia and Maricato, Élia and Cunha, Ângela and Rocha, M. Angélica M. and Santos, Sofia and Ferreira, Paula and Silva, Manuel A. and Rodrigues, Ana and Amado, Osvaldo and Coimbra, Joana and Silva, Diana and Moreira, André and Mendo, Sónia and Lopes da Silva, José A. and Pereira, Eduarda and Rocha, Sílvia M. and Coimbra, Manuel A.}, doi = {10.1039/c6gc01621a}, journal = {Green Chemistry}, month = {jan}, pages = {5331-5341}, title = {Chitosan–genipin film, a sustainable methodology for wine preservation}, url = {https://oadoi.org/10.1039/c6gc01621a}, volume = {18}, year = {2016} } @article{Pereira2015, abstract = {Many applications involving ionic liquids (ILs) require the knowledge of their interfacial behaviour, such as wettability and adhesion. In this context, herein, two approaches were combined aiming at understanding the impact of the IL chemical structures toward their wettability in both polar and non-polar surfaces, namely: (i) the experimental determination of the contact angles of a broad range of ILs (covering a wide number of anions of variable polarity, cations, and cation alkyl side chain lengths) in polar and non-polar solid substrates (glass, Al-plate, and poly-(tetrafluoroethylene) (PTFE)); and (ii) the correlation of the experimental contact angles with the cation-anion pair interaction energies generated by the Conductor-like Screening Model for Real Solvents (COSMO-RS). The combined results reveal that the ILs hydrogen-bond basicity, and thus the IL anion, plays a major role through their wettability in both polar and non-polar surfaces. The increase of the IL hydrogen-bond accepting ability leads to an improved wettability of more polar surfaces (lower contact angles) while the opposite trend is observed in non-polar surfaces. The cation nature and alkyl side chain lengths have however a smaller impact through the ILs wetting ability. Linear correlations were found between the experimental contact angles and the cation-anion hydrogen-bonding and cation ring energies, estimated using COSMO-RS, suggesting that these features primarily control the wetting ability of ILs. Furthermore, two-descriptor correlations are here proposed to predict the contact angles of a wide variety of ILs in glass, Al-plate, and PTFE surfaces. A new extended list is provided for the contact angles of ILs in three surfaces, which can be used as a priori information to choose appropriate ILs before a given application.}, author = {Pereira, Matheus M. and Kurnia, Kiki A. and Sousa, Filipa L. and Silva, Nuno J. O. and Lopes da Silva, José A. and Coutinho, Joao A. P. and Freire, Mara G.}, doi = {10.1039/c5cp05873b}, journal = {Physical Chemistry Chemical Physics}, month = {jan}, pages = {31653-31661}, title = {Contact Angles and Wettability of Ionic Liquids on Polar and Non-polar Surfaces}, url = {http://europepmc.org/articles/pmc5024753?pdf=render}, volume = {17}, year = {2015} } @article{Pinto2015, author = {Pinto, Susana C. and Rodrigues, Ana R. and Saraiva, Jorge A. and Lopes da Silva, José A.}, doi = {10.1016/j.enzmictec.2015.07.002}, journal = {Enzyme and Microbial Technology}, month = {jul}, pages = {8-18}, title = {Catalytic activity of trypsin entrapped in electrospun poly(ϵ-caprolactone) nanofibers}, url = {https://www.researchgate.net/profile/Jose_Lopes_da_Silva/publication/279737180_Catalytic_activity_of_trypsin_entrapped_in_electrospun_polye-caprolactone_nanofibers/links/55ab490408ae481aa7fbd3b4.pdf}, volume = {79-80}, year = {2015} } @article{Raguzzoni2013, author = {Raguzzoni, Josiane Callegaro and Lopes da Silva, José A. and Maraschin, Marcelo and Delgadillo, Ivonne}, doi = {10.1002/star.201200236}, journal = {Starch}, month = {nov}, pages = {938-946}, title = {Characterization of the physicochemical and thermal properties of unexplored starches with potential industrial uses from six Brazilian maize landraces}, url = {https://oadoi.org/10.1002/star.201200236}, volume = {65}, year = {2013} } @article{Rodrigues2015, abstract = {This work presents and highlights the differentiation of the physicochemical properties of the [C1Him][NTf2], [C2Him][NTf2], [1C12C1Him][NTf2], and [1C42C13C1im][NTf2] that are related with the strong bulk interaction potential, which highlights the differentiation on the physicochemical arising from the presence of the acidic group (N-H) as well as the methylation in position 2 (C(2)) of the imidazolium ring. Densities, viscosities, refractive indices and surface tensions in a wide range of temperatures, as well as, isobaric heat capacities at 298.15 K, for this IL series are presented and discussed. It was found that the volumetric properties are barely affected by the geometric and structural isomerization, following a quite regular trend. A linear correlation between the glass transition temperature, Tg, and the alkyl chain size was found; however, ILs with the acidic N-H group present a significant higher Tg than the [1CN-13C1im][NTf2] and [1CN3CNim][NTf2] series. It was found that the most viscous ILs, ([1C1Him][NTf2], [1C2Him][NTf2] and [1C12C1Him][NTf2]) have an acidic N-H group in the imidazolium ring in agreement with the observed increase of energy barrier of flow. The methylation in position 2, C(2), as well as, the N-H acidic group in the imidazolium ring, contribute to a significant variation in the cation-anion interactions and their dynamics, which is reflected in their charge distribution and polarizability leading to a significant differentiation of the refractive indices, surface tension and heat capacities. The observed differentiation of the physicochemical properties of the [1C1Him][NTf2], [1C2Him][NTf2], [1C12C1Him][NTf2], and [1C42C13C1im][NTf2] are an indication of the stronger bulk interaction potential, which highlights the effect that arises from the presence of the acidic group (N-H) as well as the methylation in position 2 of the imidazolium ring.}, author = {Rodrigues, Ana S. M. C. and Rocha, Marisa A. A. and Almeida, Hugo F. D. and Neves, Catarina M. S. S. and Lopes-Da-Silva, José A. and Freire, Mara G. and Coutinho, João A. P. and Santos, Luís M. N. B. F.}, doi = {10.1021/acs.jpcb.5b05354}, journal = {Journal of Physical Chemistry B (Soft Condensed Matter and Biophysical Chemistry)}, month = {jul}, pages = {8781-8792}, title = {Effect of the Methylation and N–H Acidic Group on the Physicochemical Properties of Imidazolium-Based Ionic Liquids}, url = {http://europepmc.org/articles/pmc5325316?pdf=render}, volume = {119}, year = {2015} } @article{Silva2015, abstract = {Mixed solutions of poly(ethylene terephthalate) (PET) and three types of poly(lactic acid) (PLA; a commercial sample and two branched PLAs) were used to prepare nonwoven nanofibrous mats by electrospinning. These mats were used as supports for trypsin immobilization, with the aim of an application in whey protein hydrolysis. Covalent attachment of crosslinked trypsin aggregates to amine-derivatized PET/PLA mats, followed by reduction with sodium cyanoborohydride, gave the best immobilized trypsin activity and showed no enzyme leaching. The activity of immobilized trypsin was higher than that of free trypsin at pH 6, a pH value representative of sweet whey. The PET/PLA mats with immobilized trypsin could be stored at 4 °C in water for at least 30 days, and could be reused 8 times without loosing activity and without enzyme leaching.}, author = {Silva, Teresa R. and Rodrigues, Daniela P. and Rocha, Jorge M. S. and Helena Gil, M. and Pinto, Susana C. S. and Lopes da Silva, José A. and Jorge Guiomar, A.}, doi = {10.1016/j.bej.2015.04.026}, journal = {Biochemical Engineering Journal}, month = {may}, pages = {48-56}, title = {Immobilization of trypsin onto poly(ethylene terephthalate)/poly(lactic acid) nonwoven nanofiber mats}, url = {https://www.researchgate.net/profile/Susana_Pinto3/publication/276421980_Immobilization_of_trypsin_onto_polyethylene_terephthalatepolylactic_acid_nonwoven_nanofiber_mats/links/56cd765e08aeb52500c267ff.pdf}, volume = {104}, year = {2015} } @article{Veleirinho2013, author = {Veleirinho, Beatriz and Berti, Fernanda V. and Dias, Paulo F. and Maraschin, Marcelo and Ribeiro-Do-Valle, Rosa M. and Lopes-Da-Silva, José A.}, doi = {10.1016/j.msec.2012.07.047}, journal = {Materials Science and Engineering: C}, month = {jan}, pages = {37-46}, title = {Manipulation of chemical composition and architecture of non-biodegradable poly(ethylene terephthalate)/chitosan fibrous scaffolds and their effects on L929 cell behavior}, url = {https://oadoi.org/10.1016/j.msec.2012.07.047}, volume = {33}, year = {2013} } @article{Veleirinho2014, abstract = {Electrospun materials have been widely explored for biomedical applications because of their advantageous characteristics, i.e., tridimensional nanofibrous structure with high surface-to-volume ratio, high porosity, and pore interconnectivity. Furthermore, considering the similarities between the nanofiber networks and the extracellular matrix (ECM), as well as the accepted role of changes in ECM for hernia repair, electrospun polymer fiber assemblies have emerged as potential materials for incisional hernia repair. In this work, we describe the application of electrospun non-absorbable mats based on poly(ethylene terephthalate) (PET) in the repair of abdominal defects, comparing the performance of these meshes with that of a commercial polypropylene mesh and a multifilament PET mesh. PET and PET/chitosan electrospun meshes revealed good performance during incisional hernia surgery, post-operative period, and no evidence of intestinal adhesion was found. The electrospun meshes were flexible with high suture retention, showing tensile strengths of 3 MPa and breaking strains of 8–33%. Nevertheless, a significant foreign body reaction (FBR) was observed in animals treated with the nanofibrous materials. Animals implanted with PET and PET/chitosan electrospun meshes (fiber diameter of 0.71±0.28 µm and 3.01±0.72 µm, respectively) showed, respectively, foreign body granuloma formation, averaging 4.2-fold and 7.4-fold greater than the control commercial mesh group (Marlex). Many foreign body giant cells (FBGC) involving nanofiber pieces were also found in the PET and PET/chitosan groups (11.9 and 19.3 times more FBGC than control, respectively). In contrast, no important FBR was observed for PET microfibers (fiber diameter = 18.9±0.21 µm). Therefore, we suggest that the reduced dimension and the high surface-to-volume ratio of the electrospun fibers caused the FBR reaction, pointing out the need for further studies to elucidate the mechanisms underlying interactions between cells/tissues and nanofibrous materials in order to gain a better understanding of the implantation risks associated with nanostructured biomaterials.}, author = {Veleirinho, Beatriz and Coelho, Daniela S. and Dias, Paulo F. and Maraschin, Marcelo and Pinto, Rúbia and Cargnin-Ferreira, Eduardo and Peixoto, Ana and Souza, José A. and Ribeiro-Do-Valle, Rosa M. and Lopes-Da-Silva, José A.}, doi = {10.1371/journal.pone.0095293}, journal = {PLoS ONE}, month = {apr}, pages = {e95293}, title = {Foreign Body Reaction Associated with PET and PET/Chitosan Electrospun Nanofibrous Abdominal Meshes}, url = {http://dx.doi.org/10.1371/journal.pone.0095293}, volume = {9}, year = {2014} }