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Nanocomplexes systems made up natural poylymers have pharmacotechnical advantages such as increase of water solubility and a decrease of drugs toxicity. Amphotericin B (AmB) is a drug apply as anti-leishmanial and anti-fungal, however it has low water solubility and high toxicity, limiting its therapeutic application. With this in mind, the present study aimed to produce nanocomplexes composed by alginate (Alg), a natural polymer, with AmB covered by nanocrystals from bacterial cellulose (CNC). For this reason, the nanocomplexes were produced utilizing sodium alginate, amphotericin B in a borate buffer (pH 11.0). The CNC was obtained by enzymatic hydrolysis of the bacterial cellulose. To CNC cover the nanocomplexes 1 ml of the nanocomplexes was added into 1 ml of 0.01% CNC suspension. The results showed an ionic adsorption of the CNC into the Alg-AmB nanocomplexes surface. This phenomena was confirmed by an increase in the particle size and PDI decrease. Besides, nanocomplexes samples covered by CNC showed uniformity. The amorphous inclusion of AmB complex into the polysaccharide chain network in both formulations. AmB in the nanocomplexes was in supper-aggregated form and showed good biocompatibility, being significantly less cytotoxic in vitro against kidney cells and significantly less hemolytic compared to the free-drug. The in vitro toxicity results indicated the Alg-AmB nanocomplexes can be considered a non-toxic alternative to improve the AmB therapeutic effect. All process to obtain nanocomplexes and it coat was conduce without organic solvents, can be considered a green process, and allowed to obtain water soluble particles. Furthermore, CNC covering the nanocomplexes brought additional protection to the system can contribut advancement in the pharmaceutical., The authors acknowledge financial support from Coordination for Higher Level Graduate Improvements (CAPES/Brazil, finance code 001), National Council for Scientific and Technological Development (CNPq/Brazil Process #428751/2016-4), and the State of São Paulo Research Foundation (FAPESP/Brazil, processes #2019/22626-5 and #2018/10508-5)., info:eu-repo/semantics/publishedVersion

Surgicel® (regenerated oxidized cellulose) is a bio-absorbable hemostatic material widely applied to prevent surgery-derived adhesions. Some critical issues have been reported associated with this biomaterial, which we aimed to overcome by producing bacterial nanocellulose (BNC) membranes with hemostatic activity, through electrochemical oxidation using the tetramethylpiperidine-1-oxyl (TEMPO) radical. Samples were characterized by FTIR, NMR, SEM, XRD and their degree of polymerization. The oxidation degree was evaluated by titration of the carboxyl groups and the hemostatic behavior by whole-blood-clotting assays. In vitro and in vivo biodegradability of oxidized BNC membranes were evaluated and compared with that of Surgicel®. The oxidation degree increased from 4% to 7% and up to 15%, corresponding to an applied charge of 400, 700 and 1200 Coulombs, respectively. The oxidized BNC preserved the crystallinity and the 3D nano-fibrillar network, and demonstrated hemostatic activity, although not as effective as that of Surgicel®. In vivo assays demonstrated that the oxidized membranes did not induce an inflammatory response, revealing a good biocompatibility. However, non-degraded oxidized BNC was still detected at the implantation site after 56 days., This work was supported by the Fundação para a Ciência e Tecnologia (FCT), under the project BioTecNorte operation (NORTE01-0145-FEDER-000004), with funding by the European Regional Development Fund under the scope of Norte2020-Programa Operacional Regional do Norte. The authors gratefully give thanks to the project NORTE-08-5369-FSE-000012, with financial support of ESF—European Social Fund, under the scope of Norte2020—Programa Operacional Regional do Norte; and to UME-UTAD for the XRD analysis., info:eu-repo/semantics/publishedVersion

The electrochemical oxidation of diclofenac (DCF), a non-steroidal anti-inflammatory drug considered as an emerging pollutant (frequently detected in wastewater), was investigated on CNT, Pt/CNT and Ru/CNT modified electrodes based on Carbon Toray in aqueous media. The electroreactivity of DCF on these modified electrodes was studied using cyclic voltammetry and the kinetic parameters were calculated from the scan rate study. Cyclic voltammograms show several oxidation processes, which confirm the interaction between DCF and the catalyst surface necessary for direct oxidation processes. Constant potential electrolysis of DCF was carried out on carbon nanotubes (CNT) and metal supported CNT (M/CNT) modified electrodes, in 0.1 M NaOH and 0.1 M Na2CO3/NaHCO3 buffer media. The highest DCF conversion (88% after 8 h of electrolysis) was found in carbonate buffer medium, for Ru/CNT, while the best carbon mineralization efficiency (corresponding to 48% of the oxidized DCF) was obtained on Pt/CNT modified electrode in 0.1 M NaOH medium. The products of the electrolyses were identified and quantified by HPLC-MS, GC-MS, HPLC-UV-RID and IC. The results show the presence of some low molecular weight carboxylic acids, confirming the cleavage of the aromatic rings during the oxidation process., he authors thank FCT (Fundação para a Cência e a Tecnologia, Portugal) for the PhD grant of Marta Ferreira, and the financing of projects: PTDC/AAGTEC/5269/2014, Centre of Chemistry (UID-QUI/00686/2013 and UID/QUI/0686/2016), and LSRE-LCM (Base Funding – UIDB/50020/2020 of the Associate Laboratory LSRE-LCM – funded by national funds through FCT/ MCTES (PIDDAC)). This work has been developed under the scope of the projects BioTecNorte (operation NORTE-01-0145- FEDER-000004), supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement through the European Regional Development Fund (ERDF). The authors also thank TUBITAK (Tu¨rkiye Bilimsel ve Teknolojik Aras-tirma Kurumu, operation TUBITAK-2219) for the post-doctoral grant to Dr Sevgi Gu¨ney., info:eu-repo/semantics/publishedVersion

Dye compounds are becoming a problematic class of pollutants for the environment, so it is important to develop stable catalysts for their elimination. First, several studies were performed with different Y zeolites (NaY, (NH4)Y and USY) in order to select the best support for the preparation of the bimetallic catalysts. In particular, NaY zeolite was used as the support for Fe, Cu and Mn metals to prepare mono and bimetallic Fenton-type catalysts by the ion exchange method. The catalysts were characterized by several techniques, such as chemical analysis, nitrogen physisorption, X-ray diffraction (XRD), scanning electron microscopy (SEM) and cyclic voltammetry studies. Characterization results revealed that the metals were successfully ion-exchanged within the NaY zeolite. The prepared catalysts were tested for the aqueous-phase degradation of dye compounds (Procion yellow (PY) and Tartrazine (Tar)) at atmospheric pressure and different temperatures, using H2O2 as the oxidant. All the investigated samples were found to be active in degrading the dyes through the Fenton-type process; however, the oxidation rate was found to be higher in the presence of the bimetallic catalysts. CuFe-NaY displays the best mineralization rate for PY oxidation while MnFe-NaY shows the highest activity for Tar degradation. This work may provide further insight into the design of Fenton-type bimetallic catalysts with improved catalytic properties for environmental remediation., This research work has been developed under the scope of the projects: BioTecNorte (operation NORTE-01-0145-FEDER-000004), supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This work also has been funded by national funds (Fundação para Ciência e Tecnologia, FCT), through the projects: PTDC/AAGTEC/5269/2014, Centre of Chemistry (UID/QUI/00686/2013 and UID/QUI/0686/2016) and Associate Laboratory LSRE-LCM-UIDB/50020/2020. OSGPS acknowledges FCT funding under the Scientific Employment Stimulus—Institutional Call CEECINST/00049/2018., info:eu-repo/semantics/publishedVersion

In the present study composites based on TiO(2 )nanoparticles, SiO2 and HY zeolite were synthesized by using a standard sol-gel methodology and analyzed by Fourier-transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy-energy-dispersive X-ray spectroscopy techniques. The photocatalysts were impregnated on cotton textiles and their photocatalytic abilities were examined by degradation of Rhodamine B (RhB) and Reactive Red 120 (RR120) dyes in aqueous solution under similar solar irradiation. RhB removal efficiencies from cotton textiles were 87%, 72% and 50% for TiO2, TiO2-SiO2-HY zeolite and TiO2-SiO2 composites, respectively and achieved after 3 h of light irradiation. However, for the RR120 dye, the reached result was different as the photodegradation for this dye (65% efficiency) was only observed in bare TiO2 functionalized textile. In addition, for the treatment with TiO2-SiO2-HY zeolite, it was found that for initial alkaline conditions at pH of the RhB dye solution, the photodegradation rate decreased., Salmon Landi Jr. thanks the Capes/Brazil for supports his Doctoral Fellowship (13346/13-0). The authors are also grateful to the financial support of the project "AIProcMat@N2020-Advanced Industrial Processes and Materials for a Sustainable Northern Region of Portugal 2020", with the reference NORTE-01-0145-FEDER-000006 and the project BioTecNorte (operation NORTE-01-0145FEDER-000004), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This work also has been funded by ERDF through COMPETE2020-Programa Operacional Competitividade e Internacionalizacao (POCI), Project POCI-01-0145-FEDER-006984 - Associate Laboratory LSRELCM and by Portuguese funds through FCT-Fundacao para a Ciencia e a Tecnologia under the Strategic Funding UID/FIS/04650/2019 as well as project PTDC/AAGTEC/5269/2014 and Centre of Chemistry (UID/QUI/00686/2013 and UID/QUI/0686/2016).

The most effective medicines available for the treatment of leishmaniasis, a life-threatening disease, exhibit serious toxicological issues. To achieve better therapeutic efficiency while decreasing toxicity associated with amphotericin B (AmB), water-soluble dextrin-AmB (Dex-AmB) formulations were developed. Self-assembled nanocomplexes were formed by dissolving Dex and AmB in alkaline borate buffer, followed by dialysis and either freeze-drying (FD) or nano spray-drying (SD), yielding water dispersible particles with a diameter of 214nm and 347nm, respectively. The very simple production process allowed the formation of amorphous inclusion complexes containing 14% of AmB in the form of monomers and water-soluble aggregates. Nanocomplexes were effective against parasites in axenic culture (IC50 of 0.056 and 0.096M for L. amazonensis and 0.030 and 0.044M for L. infantum, respectively for Dex-AmB FD and Dex-AmB SD) and in decreasing the intramacrophagic infection with L. infantum (IC50 of 0.017 and 0.023M, respectively for Dex-AmB FD and Dex-AmB SD). Also, the formulations were able to significantly reduce the cytotoxicity of AmB. Overall, this study demonstrates the suitability of dextrin as an AmB carrier and the facile and inexpensive development of a delivery system for the treatment of leishmaniasis., This work was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/ BIO/04469/2019 and BioTecNorte operation (NORTE-01-0145-FEDER000004 - Underpinning Biotechnology to foster the north of Portugal bioeconomy and NORTE-01-0145-FEDER-000012 - Structured program on bioengineered therapies for Infectious diseases and tissue regeneration) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Ricardo Silva-Carvalho gratefully acknowledge FCT for the granted scholarship (SFRH/BD/118880/2016). Karoline Rachel Melo and Moacir Fernandes Queiroz gratefully acknowledge Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Brasil for the granted scholarship., info:eu-repo/semantics/publishedVersion

Supplementary material related to this article can be found, in the online version, at doi:https://doi.org/10.1016/j.cattod.2019.06.039., The electrolysis of amoxicillin (AMX) was carried out on CNT, Pt/CNT and Ru/CNT modified electrodes based on Carbon Toray in 0.1 M NaOH, 0.1 M NaCl and 0.1 M Na2CO3/NaHCO3 buffer (pH 10) media with the aim of studying the significance of two factors, electrode material and pH, on the oxidative degradation and mineralization of AMX. For this purpose, the electrolysis products were identified by HPLC-MS and GC-MS, and quantified by HPLC-UV-RID and IC. The highest carbon mineralization efficiency, corresponding to 30 % of the oxidized AMX, was found for Pt/CNT modified electrode in carbonate buffer medium. Regarding to the AMX conversion, the results show that the effect of pH is higher than that of the electrode material. Principal component analysis allowed to determine the experimental parameters vs. product distribution relationship and to elucidate the oxidation pathways for the studied electrodes. The results show that the hydroxylation of the aromatic ring and the nitrogen atom play an important role on the efficient degradation of AMX., The authors thank FCT (Fundação para a Ciência e a Tecnologia) for the PhD grant of Marta Ferreira. This work has been developed under the scope of the projects: BioTecNorte (operation NORTE-01-0145- FEDER-000004) and “AIProcMat@N2020-Advanced Industrial Processes and Materials for a Sustainable Northern Region of Portugal 2020″, NORTE-01-0145-FEDER-000006, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This work also has been funded by national funds (FCT/MCTES (PIDDAC)) through the projects: PTDC/AAGTEC/5269/2014, Centre of Chemistry (UID/QUI/00686/2013 and UID/QUI/0686/2016) and Associate Laboratory LSRE-LCM - UID/EQU/50020/2019., info:eu-repo/semantics/publishedVersion

The decentralized production of bioelectricity as well as the bioremediation of contaminated sediments might be achieved by the incorporation of an anode into anaerobic sediments and a cathode suspended in the water column. In this context, a sediment microbial fuel cell microcosm was carried out using different configurations of electrodes and types of materials (carbon and stainless steel). The results showed a long-term continuous production of electricity (>300 days), with a maximum voltage of approximately 100 mV reached after ~30 days of operation. A twofold increase of voltage was noticed with a twofold increase of surface area (~30 mV to ~60 mV vs. 40 cm2 to 80 cm2), while a threefold increase was obtained after the substitution of a carbon anode by one of stainless steel (~20 mV to ~65 mV vs. 40 cm2 to 812 cm2). Cyclic voltammetry was used to evaluate sediment bacteria electroactivity and to determine the kinetic parameters of redox reactions. The voltammetric results showed that redox processes were limited by the diffusion step and corresponded to a quasi-reversible electron charge transfer. These results are encouraging and give important information for the further optimization of sediment microbial fuel cell performance towards the long-term operation of sediment microbial fuel cell devices., This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 — Programa Operacional Regional doNorte. The authors also acknowledge the fellowship awarded to Gilberto Martins (SFRH/BPD/80528/2011) under the scope of the program POPH/ESF., info:eu-repo/semantics/publishedVersion

This work reports the synthesis of nanocomposite photocatalytic materials based on nitrogen-doped TiO2nano, SiO2 and different percentages of HY zeolite (0, 12, 25 and 50%). These materials were characterized by using Fourier transformed infrared spectroscopy, X-ray diffraction, N2 adsorptiondesorption, UV-vis diffuse reflectance spectroscopy and scanning electron microscopy. The nanocomposites, which presented an energy band gap of about 3.03 eV, were immobilized on cotton fabric and their self-cleaning properties were investigated by decolourization of rhodamine B (RhB) dye in aqueous solution under simulated solar irradiation. The fabrics coated with the photocatalysts, containing and not containing zeolites, showed the same RhB decolourization (about 95%) after 5 h, excluding the situation where a large amount of HY (50%) was used in the nanocomposites. However, results obtained from high performance liquid chromatography analysis depicted that in the presence of the HY zeolite a more effective RhB degradation was achieved. In fact, even after the use of five consecutive cycles, the RhB decolourization remained high (about 85%). Generally, the photodegradation of RhB solution in the presence of cotton fabrics functionalized with TiO2nano, TiO2nano-SiO2 and TiO2nano-SiO2-0.25 HY resulted in the formation of products that exhibited a similar cytotoxic effect when compared to the untreated RhB solution and subjected to the same tested concentrations and incubation times., Salmon Landi Jr. thanks the Capes from Brazil for supports his Doctoral Fellowship (Proc. no. 13346/13-0). The authors are also grateful to the financial support of the project “AIProcMat@N2020 – Advanced Industrial Processes and Materials for a Sustainable Northern Region of Portugal 2020”, with the reference NORTE-01-0145-FEDER-000006 and the project BioTecNorte (operation NORTE-01-0145-FEDER-000004) supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This work also has been funded by ERDF through COMPETE2020 – Programa Operacional Competitividade e Internacionalizac¸ão (POCI), Project POCI-01-0145-FEDER006984 – Associate Laboratory LSRE-LCM and by national funds through FCT – Fundac¸ão para a Ciência e a Tecnologia for project PTDC/AAGTEC/5269/2014 and Centre of Chemistry (UID/QUI/00686/2013 and UID/QUI/0686/2016). Artur Ribeiro thanks FCT for the SFRH\BPD\98388\2013 grant., info:eu-repo/semantics/publishedVersion

The electroreactivity of amoxicillin (AMX) was studied on catalysts based on platinum, palladium and ruthenium supported on carbon nanotubes (Pt/CNT, Pd/CNT, Ru/CNT) in aqueous media using cyclic voltammetry. Cyclic voltammograms show two oxidation processes, the first one between 0.5 and 1.0 V vs. reference hydrogen electrode (RHE) and the second one between 1.2 and 1.6 V vs. RHE. The effects of electrocatalytic material and supporting electrolyte, on current intensities and oxidation potentials, were determined using experimental design strategy (DOE). Kinetic parameters of the oxidation reactions were calculated from the scan rate study. The constant potential electrolysis of AMX was carried out on Ru/CNT catalyst, in 0.1 M NaOH and AMX conversion reached 45 % after 6 h of electrolysis at 2.5 V vs. RHE. The percentages of CO32, SO42 and NO3 among oxidation products were 18, 15 and 2%, respectively. The primary degradation products of AMX determined by HPLCMS gave some insight about the reaction pathways., The authors thank FCT (Fundação para a Ciência e a Tecnologia) for the PhD grant of Marta Ferreira. This work is also a result of project BioTecNorte (operation NORTE-01-0145-FEDER-000004) and AIProcMat@N2020 (operation NORTE-01-0145-FEDER000006), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement through the European Regional Development Fund (ERDF). This work also has been funded by ERDF through COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI), POCI-01-0145-FEDER-006984 – Associate Laboratory LSRE-LCM, and by national funds through FCT for PTDC/AAGTEC/5269/2014 and Centre of Chemistry (UID/QUI/ 00686/2013 and UID/QUI/0686/2016)., info:eu-repo/semantics/publishedVersion

The presence of two metals (M1M2) in a zeolite structure enhances the degradation of pollutants in liquid or gas phase comparing to monometallic catalysts. In this work, the complete oxidation of ethyl acetate into CO2 was achieved by metal catalysts based on NaY zeolite prepared by the ion-exchange method. The metal zeolite catalysts were optimized by used several parameters: (i) the presence of a second metal in M1M2 catalysts; (ii) the presence or not of a noble metal in the pair CuM2 (M2=Pd, Zn or Ag); (iii) the order of introduction of the metals in M1M2 catalysts (CuPd or PdCu); (iv) particle size of NaY and NaYnano; and (v) the effect of simultaneously adding metal species (Cu and Pd). M1M2 catalysts presented the best results compared to the monometallic catalysts and the presence of a noble metal in M1M2 catalysts enhanced their acivity. Among the metal phases studied, the catalyst (CuPd)0.01-Y was shown to be the most efficient for this application., This work has been developed under the scope of the projects: BioTecNorte (operation NORTE-01-0145-FEDER-000004) and “AIProcMat@N2020-Advanced Industrial Processes and Materials for a Sustainable Northern Region of Portugal 2020”, NORTE-01-0145FEDER-000006, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This work also has been funded by national funds (FCT, Fundação para a Ciência e a Tecnologia), through the projects: PTDC/AAGTEC/5269/2014, Centre of Chemistry (UID/QUI/ 00686/2013 and UID/QUI/0686/2016) and LSRE/LCM (POCI-010145-FEDER-006984)., info:eu-repo/semantics/publishedVersion

Reduced graphene oxide (RGO) and titanium dioxide (TiO2) nanoparticles were immobilized on cotton textile substrates to produce self-cleaning textiles. Varying number of layers of RGO andTiO(2) nanoparticles were coated by a facile method, and their photocatalytic potential was evaluated by measuring the degradation rate of rhodamine B (Rh-B) in an aqueous solution in a photoreactor under simulated solar irradiation. X-ray diffraction (XRD) and zeta potential measurements of starting materials were studied as they are crucial for innovative methods of functionalization. The study confirms that it is possible to ensure a good adhesion of nanoparticles on textile samples without the use of a resin. The application of varying number of RGO and TiO2 coatings has influence on photocatalytic properties of functionalized cotton textile substrates. The energy band gap of the samples reduces from 3.25 to -3.20 eV with the number of RGO coatings. All five de-ethylated intermediates of Rh-B during the photocatalytic degradation were identified using a high-performance liquid chromatography-mass spectrometry method. The experimental results show that, in general, the higher the number of RGO coatings is, the higher the photocatalytic efficiency (eta) of the functionalized substrate is (eta= 87% for three RGO coatings on TiO2)., S. Landi Jr. expresses his gratitude to the Brazilian Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) for sporting his Doctoral Fellowship performed in Physics Centre at University of Minho. J. Molina wishes to thank the Spanish Ministerio de Ciencia e Innovacion (contract CTM2011-23583) for the financial support. Moreover, the authors still want to thank the Portuguese Foundation for Science and Technology (FCT) for its contribution in financial support of this research work., info:eu-repo/semantics/publishedVersion

This work is devoted to study the photocatalytic ability of cotton textiles functionalized with SiO2-TiO2 and SiO2-TiO2-HY composites to degrade a dye molecule. Coatings were prepared by sol-gel method and calcined at different temperatures in a range of 400–750 °C. FTIR confirmed the existence of SiOTi bounds and the band located in the region between 570 and 600 cm−1 was used to calculate the framework Si/Al ratio of HY in the SiO2-TiO2-HY composites. XRD confirmed the presence of nanosized TiO2 (anatase phase) in all calcined composites. Nitrogen adsorption isotherms showed a decrease in surface area and pore volume for higher calcination temperature. A simple mechanical process was used to impregnate the different composites on the cotton substrates. The photocatalytic activity of cotton textiles functionalized with SiO2-TiO2 and SiO2-TiO2-HY composites was tested via the degradation of Rhodamine B (RhB) dye under similar solar irradiation. The best catalytic performance was achieved with the SiO2-TiO2 and SiO2-TiO2-HY composites subjected to a calcination treatment at 400 °C, whereas SiO2-TiO2 presented a decolourization and mineralization around 94% and 89%, respectively, after 2 h of irradiation. Furthermore, the products of RhB degradation were analysed and identified by using HPLC-ESI–MS and ion chromatography techniques and a photocatalytic mechanism was proposed., The authors thank CAPES from Brazil for the financial support of this work. This work is also a result of project “AIProcMat@N2020 − Advanced Industrial Processes and Materials for a Sustainable Northern Region of Portugal 2020”, with the reference NORTE-01-0145-FEDER-000006 and the project BioTecNorte (operation NORTE-01-0145-FEDER-000004), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This work also has been funded by ERDF through COMPETE2020 − Programa Operacional Competitividade e Internacionalização (POCI), Project POCI-01-0145-FEDER-006984 − Associate Laboratory LSRE-LCM and by national funds through FCT − Fundacão para a Ciência e a Tecnologia for project PTDC/AAGTEC/5269/2014 and Centre of Chemistry (UID/QUI/00686/2013 and UID/QUI/0686/2016)., info:eu-repo/semantics/publishedVersion

Several silica microporous structures have been studied for their potential as drug delivery systems (DDS) over the last years. However, systematic studies comparing host structures with different topologies and particle sizes, and toxicity studies to human cancer cells, are scarce. In the present work, 3D crystalline structures, three different zeolites (large, medium and small pore size) and one titanosilicate (large pore size) were used as hosts for loading 5-fluorouracil (5-FU), an anticancer drug currently used to treat several malignant tumors. Here, we (i) compared the loading capacity and drug release profiles of the different hosts in simulated body fluid conditions, including host structure stability studies; (ii) established the kinetic parameters for the release of 5-FU and (iii) studied the effect of 5-FU encapsulation in the viability of human breast and colon cancer cells, with determination of the potentiation factor. The loading capacity and the release profile of the DDS were revealed to be dependent on the porous framework of the host structures. Decrease in pH to 2.0 (simulation of gastro-intestinal fluid), showed stability of the host structures, with minimal leaching of Al3+ and no Ti4+ for long periods of time (up to 72 h). All DDS drug release profiles fitted the Weibull model. These silica microporous structures were revealed to be non-toxic to the cancer cells, while all DDS endorsed the important 5-FU potentiation effect on cell viability., N. V., F. M. S. and R. A. are recipients of PhD fellowships (SFRH/BD/97797/2013, SFRH/BD/87139/2012 and SFRH/BD/98002/2013) from Foundation for Science and Technology (FCT, Portugal). MS also acknowledges FCT for a post-doc grant (SFRH/BPD/65978/2009). This work has been developed under the scope of the project NORTE-01-0145-FEDER-000013 and the project BioTecNorte (operation NORTE-01-0145-FEDER-000004), supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER). This work also has been funded by national funds (FCT), through the projects: Centre of Chemistry (UID/QUI/00686/2013 and UID/QUI/0686/2016); CICECO (PEst-C/CTM/LA0011/2013, F-COMP-01-0124-FEDER-037271); LSRE/LCM (POCI-01-0145-FEDER-006984) and ICVS/3B's (POCI-01-0145-FEDER-007038)., info:eu-repo/semantics/publishedVersion

Constant current and constant potential electrolyses of oxalic and oxamic acids were carried out on multiwalled carbon nanotubes (CNT) and on monometallic (Pd and Pt) and bimetallic (Ru–Cu) catalysts supported on multiwalled carbon nanotubes. Both carboxylic acids were mineralized with high conversions via hypochlorite ion produced in situ, in 0.10 M NaCl medium. Highest current efficiency, corresponding to 97%, and highest reaction rate constant for oxalic acid mineralization were obtained for the Ru–Cu/CNT modified electrode, in 0.10 M NaCl medium. The mineralization of oxamic acid was achieved with a faradic yield of 96% and an energy consumption of 14.6 kWh (kg of pollutant)−1in the same medium. The conversion values obtained for the oxidation of oxalic acid in 0.50 M NaOH medium, on Pt/CNT, Pd/CNT and Ru–Cu/CNT modified electrodes, were respectively 42%, 60% and 85%. In this last medium, 88% of the initial oxamic acid (15.8 mM) was transformed to carbonate ion and nitrogen at Pt/CNT modified anode.

The manganese(III) complex with a Schiff-base salen-type ligand (1,5-bis{[(1E)-(2-hydroxyphenyl)methylene]amino}-1H-imidazole-4-carbonitrile) has been encapsulated in the nanopores of a Y zeolite by using two different methodologies, the flexible ligand and in situ complex preparation methods. Cyclic voltammetry studies revealed that the neat complex undergoes reversible oxidation in dmf, which has been attributed to the MnII/III redox couple, whereas the two heterogeneous catalysts show different electrochemical behaviour in aqueous medium. The encapsulated and non-encapsulated homogeneous MnIIIsalen complexes were screened as catalysts for olefin oxidation by using tBuOOH as the oxygen source in different solvents. Under the optimized conditions, the catalysts exhibited moderate activity. Both heterogeneous catalysts catalysed the oxidation of cyclohexene with tBuOOH, primarily to give the allylic oxidation products. These catalysts were found to be reusable after the catalytic cycle, but with some loss of activity. A DFT study confirmed the distortion of the complex in the zeolite cage, the main difference being observed for the bonded chloride., I. K.- B. thanks the Fundacao do Ministério de Ciência e Tecnologia (FCT) for a contract under the program Ciência 2007. The authors thank the FCT and the Fundo Europeu de Desenvolvimento Regional (FEDER)) [COMPETE-QREN-EU, grant number PEst-C/QUI/UI0686/2011 (FCOMP-01-0124-FEDER-022716)] for financial support to the Research Centre at the Centro de Quimica, Universidade do Minho.

"Published online: 17 June 2016", Asparaginase reduces the levels of asparagine in blood, which is an essential amino acid for the proliferation of lymphoblastic malign cells. Asparaginase converts asparagine into aspartic acid and ammonia. The accumulation of ammonia in the bloodstream leads to hyperammonemia, described as one of the most significant side effects of asparaginase therapy. Therefore, there is a need for asparaginase formulations with the potential to reduce hyperammonemia. We incorporated 2 % of therapeutic enzyme in albumin-based capsules. The presence of asparaginase in the interface of bovine serum albumin (BSA) capsules showed the ability to hydrolyze the asparagine and retain the forming ammonia at the surface of the capsules. The incorporation of Poloxamer 407 in the capsule formulation further increased the ratio aspartic acid/ammonia from 1.92 to 2.46 (and 1.10 from the free enzyme), decreasing the levels of free ammonia. This capacity to retain ammonia can be due to electrostatic interactions and retention of ammonia at the surface of the capsules. The developed BSA/asparaginase capsules did not cause significant cytotoxic effect on mouse leukemic macrophage cell line RAW 264.7. The new BSA/asparaginase capsules could potentially be used in the treatment of acute lymphoblastic leukemia preventing hyperammonemia associated with acute lymphoblastic leukemia (ALL) treatment with asparaginase., Fundação para a Ciência e a Tecnologia - SFRH\BPD\98388\2013 ; UID/BIO/04469/2013 ; UID/BIA/04050/2013, COMPETE 2020 (POCI-01-0145-FEDER-006684)

In recent years, new textile materials have been developed through the use of nanotechnology-based tools. The development of textile surfaces with self-cleaning properties has a large combined potential to reduce the environmental impact related to pollution. In this research work, three types of textiles substrates (cotton, Entretela, and polylactic acid (PLA)) were functionalized with titanium dioxide nanoparticles (TiO2) using chemical and mechanical processes (padding). During the functionalization process, two different methods were used, both of which allowed a good fixation of nanoparticles of TiO2 on textile substrates. The samples were examined for morphology and for photocatalytic properties under visible light irradiation. A study aimed at evaluating the effect of pH of the aqueous solution of TiO2 nanoparticles was performed in order to promote interaction between TiO2 and the dye solution rhodamine B (Rh-B). The TiO2 nanoparticles were characterized by X-ray diffraction (XRD). The measurement of the zeta potential of the TiO2 nanoparticle solution proved to be always positive and have low colloidal stability. Chromatography (HPLC and GC-MS) analyses confirmthat oxalic acid is the intermediate compound formed during the photodegradation process., The authors would like to acknowledge FCT—Fundacão para a Ciência e Tecnologia—for funding under the Project PTDC/FIS/120412/2010, “NanoEcoBuild: Nanobased concepts for Innovative&Eco sustainable Constructive Material’s Surfaces,” and the European Commission through FP7 PEOPLE-2010-IRSES-NanoCIS(269279) project., info:eu-repo/semantics/publishedVersion

Phenol was successfully oxidized by the heterogeneous catalysts based on iron(II) or copper(II) pyrrolylazine complexes encapsulated into NaY zeolite, under mild conditions. The heterogeneous catalysts were prepared using two different methods and characterized by different spectroscopic techniques and chemical analysis. The pyrrolyl-azine complexes are formed with a metal/ligand molar ratio of 2:1. Their structures were further confirmed by OFF calculations. The catalytic experimental conditions (e.g., amount of catalyst, presence or absence of the oxidant, PhOH:tBuOOH molar ratio) were optimized. The presence of the encapsulated metal pyrrolyl-azine complexes in NaY zeolite enhances higher conversion of phenol to catechol. The catalytic activities of the encapsulated metal complexes in NaY zeolite were compared with the homogeneous counterpart, and the catalysts were easily recovered and reused., IKB thanks to Foundation for the Science and Technology (FCT, Portugal), for the contract under 'Programa Ciencia 2007 and for the contract under the project "n-STeP - Nanostructured systems for Tail" (NORTE-07-0124-FEDER-000039, supported by Programa Operacional Regional do Norte (ON.2). FCT and FEDER (European Fund for Regional Development)-COMPETE-QREN-EU for financial support to the Research Centres, MUM [PEst-C/QUI/UI0686/2013 (F-COMP-01-0124-FEDER-037302) and project NORTE-07-0124-FEDER-000039. This work is funded also by FEDER funds through the Operational Programme for Competitiveness Factors COMPETE and by National Funds through FCT - Foundation for Science and Technology under the grant PEST-C/EQB/LA0006/2013/37285. FCT is also acknowledged for financial support to the NMR Portuguese network (PTNMR, Bruker Avance III 400-Univ. Minho). Also, the authors are grateful to Dr A. S. Azevedo for collecting the powder diffraction data., info:eu-repo/semantics/publishedVersion

The 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 at 40 °C during 18 h in water bath with mechanical stirring or 1 h in ultrasonic bath followed by 6 h in vacuum in both the cases for evaporation of ethyl acetate. The application of ultrasound significantly intensified the polyesterification reaction with reduction of the processing time from 24 to 7 h. The same degree of polymerization was obtained for the same enzyme loading in less time of reaction when using the ultrasound treatment. The degree of polymerization for long-term polyesterification was improved approximately 8-fold due to the presence of sonication during the reaction. The highest degree of polymerization achieved was 31, with a monomer conversion of 96.77%. The ultrasound treatment demonstrated to be an effective green approach to intensify the polyesterification reaction with enhanced initial kinetics and high degree of polymerization., This study was supported by Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684). The work was also supported by Bioprocess and Bionanotechnology Research Group (BBRG) of Minho University and the Post Graduate Funding Program of Jiangnan University for Overseas Study. All authors also acknowledge the funding of Department of Science and Technology and Portuguese Science Foundation under the Indo-Portuguese collaborative program.

This study investigates the functionalization of titanium dioxide nanoparticles on the surface of polymeric microcapsules as a mean to control the release of encapsulated citronella through solar radiation. This allows for the release of a mosquito repellent without human intervention, as the sunlight works as a release activator. The TiO2 nanoparticles were synthetized using a modified sol–gel and hydrothermal method, with a crystallite size of the order of 10 nm and a specific surface area >250 m2/g. Transmission electron microscopy observations enabled the confirmation of the mesoporous structure. The nitrogen doping effect and changes in pH (pH = 3, 6 and 9) of the precursor solution was studied from photocatalytic and photoluminescence experiments. Polyurethane microcapsules were prepared using a modified interfacial polymerization method. The surface topography ofthe microcapsules was observed with scanning electron microscopy, while the release efficiency was quantified using gas chromatography coupled with mass spectroscopy. In-vitro bioassays using live mosquitoes further attested the controlled release repellence effect of these photocatalytic microcapsules by inhibition of these vectors. The results showed that functionalizing the microcapsules with nanoparticles on their surface and then exposing them to ultraviolet radiation effectively increased the output of citronella into the air, repelling the mosquitoes, This work was supported by FEDER through the COMPETE Program and by the Portuguese Foundation for Science and Technology (FCT) in the framework of the PTDC/CTM-NAN/119979/2010 project. Juliana Marques acknowledges the FCT supportfor her PhD grant SFRH/BD/112868/2015. The authors would like to acknowledge Dr C. Mateos-Pedrero for the BET surface area analysis.

Peroxidases can be used in decolorization processes and the treatment of textiles effluents. This study evaluates the potential of the turnip peroxidase enzyme in the decolorization of the phthalocyanine textile dye Reactive Blue 21 (RB21). Some factors such as pH, the amount of H2O2 and the enzyme were evaluated in order to determine the optimum conditions for the enzyme performance. The reaction products formed during the decolorization of the RB21 dye were analyzed by high-performance liquid chromatography–mass spectrometry coupling (LC–ESI/MS). LC–ESI/MS analysis showed that the decolorization of the dye RB21 by turnip peroxidase is due to the breaking up of the chromatogenous system. The tests for toxicity towards lettuce seeds showed an increase of the toxicity after enzymatic treatment of the dye. This study verifies the viability of the use of the turnip peroxidase enzyme in the biodegradation of textile dyes., FAPEMIG, CNPq, CAPES

The electrochemical oxidation of oxalic and oxamic acids on multiwalled carbon nanotubes (CNT) and on monometallic (Pd and Pt) and bimetallic (Pd-Cu, Pt-Cu) catalysts supported on multiwalled carbon nanotubes was investigated using cyclic voltammetry. The electrodes were prepared by dispersion of the catalytic material on Toray carbon (CT) using a Nafion/water solution. The kinetic parameters of the reactions were determined using cyclic voltammetry. Modification of Toray carbon electrode with carbon nanotubes enables the oxidation of oxalic and oxamic acids in the solvent stability region. The highest oxidation current densities were observed for the Pt-Cu/CNT/CT electrode in 0.1 M NaCl. The oxidation potentials for both oxalic and oxamic acids in this case were lower than those observed with the CNT/CT electrode. The prepared electrocatalysts show good mechanical and chemical stability., Support for this work was provided by the project NANO/NTec-CA/0122/2007 financed by Fundacao para a Ciencia e a Tecnologia (FCT), Portugal and FEDER, in the context of Programme COMPETE.

The concentrations of all components in the phases of aqueous two-phase polyethylene glycol–sodium sulfate system of a fixed composition with different concentrations of NaCl additive were determined. Solvatochromic solvent features of aqueous media in the phases of all the systems were characterized in terms of solvent dipolarity/polarizability, solvent hydrogen bond donor acidity and hydrogen bond acceptor basicity. Partitioning of a homologous series of dinitrophenylated amino acids with aliphatic alkyl side chain was examined in all the systems, and the differences between the relative hydrophobicity and electrostatic properties of the phases were quantified. These differences were described in terms of solvatochromic solvent features of the phases. The previously reported partition coefficients of twelve different nonionic compounds in all the systems were expressed in terms of solute descriptors. It is demonstrated that two solvatochromic solvent descriptors (solvent dipolarity/polarizability, and solvent hydrogen bond donor acidity) could adequately describe the partitioning of the solutes in all the systems employed., Luisa A. Ferreira acknowledges the financial support (SFRH/BPD/47607/2008) from Fundacao para a Ciencia e a Tecnologia (Lisboa, Portugal).

The electroactivity of zeolite-encapsulated redox-active transition metal complexes was explored for copper(II)-PAN (PAN = 1-(2-pyridylazo)-2-naphthol) complex encaged in the supercages of Y zeolite. Copper(II)-PAN complex and the zeolite boundary were investigated electrochemically by dispersion with a Nafion/water solution on carbon Toray as supporting electrode. Encapsulation was achieved by: (i) ion exchange of copper(II) in NaY zeolite and (ii) coordination of the intrazeolite metal ion with the PAN ligand using an L:copper(II) molar ratio of 2:1. The resulting materials were characterized by cyclic voltammetry in zeolite modified electrodes, surface analysis (XPS, SEM and XRD), spectroscopic methods (EPR and FTIR) and chemical analysis, which indicated that the copper(II)-PAN complex was effectively encapsulated inside the supercages of NaY, without any modification of the morphology and structure of the zeolite. The coordination geometry of Y-encapsulated copper(II)-PAN complex has been obtained with preferentially 1:1 stoichiometry analogous to the model complex, [CuCl(PAN)], by molecular simulations. For the cyclic voltammetry studies, the electrochemical behavior of free complex was compared with copper(II)-PAN complex encapsulated in Y zeolite. The results show evidence for electroactivity restricted to the boundary associated to the copper(II)-PAN complex.

The oxidation of d -mannose is studied on platinum, gold and nickel in alkaline medium. The electro-reactivity of this compound and the rate determining step of the reactions were determined by cyclic voltammetry. Lead adatoms have important effect on the oxidation of d -mannose on platinum electrode. Five folder of increase in current densities was observed after the addition of 10−6 M Pb2+. Electrolyses carried out on upd-lead modified platinum, and gold electrodes show good conversion yields (75% and 80%, respectively) and reasonable selectivities towards mannonic acid. High amount of cleavage products were detected at the end of the electrolysis at nickel electrode. The reactivity-functional group relationship has been discussed considering the results of the electrolyses.

The aim of this study was to evaluate tetracycline antibiotic (TA) removal from contaminated water by Moringa oleifera seed preparations. The composition of synthetic water approximate river natural contaminated water and TA simulated its presence as an emerging pollutant. Interactions between TA and protein preparations (extract; fraction and lectin) were also evaluated. TA was determined by solid phase extraction followed by high performance liquid chromatography - mass spectrometry. Moringa extract and flour removed TA from water. Extract removed TA in all concentrations and better removal (40%) was obtained with 40 mg L1; seed flour (particles < 5mm), 1.25 g L1 and 2.50 g L1 removed 28 and 29% of tetracycline, respectively; particles > 5 mm (0.50 g L1) removed 55% of antibiotic. Interactions between TA and seed preparations were assayed by haemagglutinating activity (HA). Specific HA (SHA) of extract (pH 7) was abolished with tetracycline (5 mg L1); fraction (75%) and lectin HA (97%) were inhibited with TA. Extract SHA decreased by 75% at pH 8. Zeta potential (ZP) of extract 700 mg L1 and tetracycline 50 mg L1 , pH range 5 to 8, showed different results. Extract ZP was more negative (10.73 mV to 16.00 mV) than tetracycline ZP (0.27 mV to 20.15 mV); ZP difference was greater in pH 8. The focus of this study was achieved since moringa preparations removed TA from water and compounds interacting with tetracycline involved at least lectin binding sites. This is a natural process, which do not promote environmental damage., This work was supported by the Fundacao para a Ciencia e a Tecnologia and POPH/FSE under Grant SFRH/BPD/37349/2007; the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) for fellowships (PMGP and LCBBC); the authors thank the FCT Strategic Project of UID/BIO/04469/2013 unit, the project RECI/BBB-EBI/0179/2012 [FCOMP-01-0124-FEDER-027462] and the project 'BioInd - Biotechnology and Bioengineering for improved Industrial and Agro-Food processes,' REF. NORTE-07-0124-FEDER-000028 Co-funded by the Programa Operacional Regional do Norte (ON.2 - O Novo Norte), QREN, FEDER.

The electrochemical mineralization of aniline, a compound that causes serious environmental problems, was investigated at Pt, Pd and Ru-Cu catalysts supported on multiwalled carbon nanotubes (CNTs). The modified electrodes, based on commercial CNT samples, were prepared and dispersed onto Toray carbon (CT) using a Nafion/water solution. The electroreactivity of aniline at the electrocatalysts based on CNTs, and the kinetic parameters of the redox reactions, were determined using cyclic voltammetry. In order to determine the conditions that allow an efficient mineralization, the electrochemical oxidation of aniline was carried out in a membrane separated electrochemical cell. The reaction products were identified and quantified using chromatographic methods in order to evaluate the mineralization efficiency. The highest conversions were obtained with the Ru-Cu/CNT/CT modified electrode., O.S.G.P. Soares acknowledges FCT for grant SFRH/BPD/80435/2011. The LCM group acknowledges the support by PEst-C/EQB/LA0020/2013, financed by FEDER through COMPETE – Programa Operacional Factores de Competitividade, and by FCT – Fundação para a Ciência e a Tecnologia; NORTE-07-0124-FEDER-0000015 and NORTE-07-0162-FEDER-000050, financed by QREN, ON2 and FEDER. This work was also supported by the Centre of Chemistry (University of Minho, Portugal), through the projects PEst-C/QUI/UI0686/2013 (F-COMP-01-0124-FEDER-037302) and n-STeP Project, reference NORTE-07-0124-FEDER-000039, supported by the Programa Operacional Regional do Norte (ON.2)., info:eu-repo/semantics/publishedVersion

The effect of the molecular structure of monosaccharides on their electrochemical behavior at a gold electrode in alkaline medium was investigated in order to elucidate the relation between the structure and electro-reactivity. The oxidation of the aldehyde hydrate (or hemiacetal) at C1 carbon atom is the easiest occurring at E

The electrocatalytic oxidation of d -galactose was investigated on platinum, gold and nickel electrodes in 0.1 M NaOH medium. The oxidation of galactose on nickel takes place in the NiOOH region and leads to the cleavage of the C–C bonds. This was confirmed by HPLC analyses of electrolyzed solutions which demonstrate relatively high amounts of low molar mass carboxylic acids, i.e., formic and glycolic acids. The oxidation of galactose on platinum is initiated at very low potentials, i.e., −0.8 V vs. SCE probably without oxygenated species on the electrode surface and gives moderate selectivity towards galactonic acid. The important effect of the lead adatoms on the electrocatalytic properties of platinum was demonstrated by the increase in the yield of galactonic acid from 34% to 67% with addition of 10 −5 M Pb 2+ . On gold, galactose oxidation begins at approximately −0.5 V vs. SCE and is probably catalysed by the presence of hydrous gold oxides. The best yield of galactonic acid, 86%, was obtained after 6 h of electrolysis using a two potential program: −0.1 V vs. SCE for 30 s, 1.5 V for 1 s.

The electrocatalytic oxidation of d -xylose was performed in alkaline medium at both platinum and gold electrodes. The higher catalytic activity of gold was clearly demonstrated. Cyclic voltammetric studies were performed in a wide range of sweep rates (0.010–1.00 V s −1 ), various concentrations of d -xylose and of hydroxide. The influence of temperature was also studied. Kinetic data was obtained. The chromatographic analysis has identified xylonic acid (0.5 to 5×10 −3 mol dm −3 ) as the main oxidation product produced during the electrolysis of d -xylose, on Pt and Au electrodes, respectively, at potentials corresponding to the main oxidation peaks. The d -xylose conversion yield was found to be higher on Au than on Pt (98% against 26%). Other carboxylic acids, in concentrations lower than 10 −3 mol dm −3 , were identified by high-performance liquid chromatography (HPLC), as secondary products, namely glyceric; glycolic and formic acids, during the electrolysis on both electrode materials. On the other hand, tartaric (4.6%) and glyoxilic acids (14.0%) have been identified during the electrolysis on Au and Pt electrodes, respectively. Traces of tartronic and of oxalic acids have also been identified. HPLC studies have demonstrated the higher selectivity of Au electrodes for the production of xylonic acid.

In this study we propose a suitable method for the solar-activated controlled release of volatile compounds from polymeric microcapsules bonded with photocatalytic nanoparticles. These reservoirs can find applications, for example, in the controlled release of insecticides, repellents, or fragrances, amongst other substances. The surfaces of the microcapsules have been functionalized with TiO2 nanoparticles.Upon ultraviolet irradiation, redox mechanisms are initiated on the semiconductor surface resulting in the dissociation of the polymer chains of the capsule wall and, finally, volatilization of the encapsulated compounds. The quantification of the output release has been performed by gas chromatography analysis coupled with mass spectroscopy., Strategic Project PEST-C/FIS/UI607/2011 and PTDC/CTMNAN/119979/2010 Project

The studies of potentiation of 5-fluorouracil (5-FU), a traditional drug used in the treatment of several cancers, including colorectal (CRC), were carried out with zeolites Faujasite in the sodium form, with different particle sizes (NaY, 700nm and nanoNaY, 150nm) and Linde type L in the potassium form (LTL) with a particle size of 80nm. 5-FU was loaded into zeolites by liquid-phase adsorption. Characterization by spectroscopic techniques (FTIR, 1H NMR and 13C and 27Al solid-state MAS NMR), chemical analysis, thermal analysis (TGA), nitrogen adsorption isotherms and scanning electron microscopy (SEM), demonstrated the successful loading of 5-FU into the zeolite hosts. In vitro drug release studies (PBS buffer pH 7.4, 37°C) revealed the release of 80-90% of 5-FU in the first 10min. To ascertain the drug release kinetics, the release profiles were fitted to zero-order, first-order, Higuchi, Hixson-Crowell, Korsmeyer-Peppas and Weibull kinetic models. The in vitro dissolution from the drug delivery systems (DDS) was explained by the Weibull model. The DDS efficacy was evaluated using two human colorectal carcinoma cell lines, HCT-15 and RKO. Unloaded zeolites presented no toxicity to both cancer cells, while all DDS allowed an important potentiation of the 5-FU effect on the cell viability. Immunofluorescence studies provided evidence for zeolite-cell internalization., RA is recipient of fellowship SFRH/BI/51118/2010 from Fundacao para a Ciencia e a Tecnologia (FCT, Portugal). This work was supported by the FCT projects refs. PEst-C/QUI/UI0686/2011 and PEst-C/CTM/LA0011/2011 and the Centre of Chemistry and Life and Health Sciences Research Institute (University of Minho, Portugal). The NMR spectrometer is part of the National NMR Network (RNRMN), supported with funds from FCT/QREN (Quadro de Referencia Estrategico Nacional).

The biological oxygen demand (BOD) may be the most used test to assess the amount of pollutant organic matter in water; however, it is time and labor consuming, and is done ex-situ. A BOD biosensor based on the microbial fuel cell principle was tested for online and in situ monitoring of biodegradable organic content of domestic wastewater. A stable current density of 282±23 mA/m2 was obtained with domestic wastewater containing a BOD5 of 317±15 mg O2/L at 22±2 °C, 1.53±0.04 mS/cm and pH 6.9±0.1. The current density showed a linear relationship with BOD5 concentration ranging from 17±0.5 mg O2/L to 78±7.6 mg O2/L. The current generation from the BOD biosensor was dependent on the measurement conditions such as temperature, conductivity, and pH. Thus, a correction factor should be applied to measurements done under different environmental conditions from the ones used in the calibration. These results provide useful information for the development of a biosensor for real-time in situ monitoring of wastewater quality., Fundação para a Ciência e a Tecnologia (FCT)

The goal of this study is the preparation of new heterogeneous catalytic materials to be used in oxidation reactions under mild conditions through the valuation of heavy metals in wastewater. The samples used in the immobilization of chromium complexes were prepared from a dichromate solution of 100 mgCr L−1. The zeolite CrNaY was prepared from a robust biosorption system consisting of a bacterial biofilm, Arthrobacter viscosus, supported on zeolite NaY. The biofilm performs the reduction of Cr(VI) to Cr(III) and this cation is retained in the zeolite by ion exchange. The immobilization of chromium complexes with heterocyclic ligands in the supercages of Y zeolite was performed by the in situ synthesis with three different ligands, 3-methoxy-6-chloropyridazine (A), 3-piperidino-6-chloropyridazine (B) and 1-(2-pyridylazo)-2-naphthol (C). A sample loaded with Cr from a liquid solution with the same initial concentration was prepared as a reference through the traditional direct ion-exchange method and coordinated with ligand (A). The resulting catalysts were fully characterized by different techniques (FTIR, XRD, TGA, SEM, Raman, cyclic voltammetric studies and chemical analysis) and the results confirmed that the Cr complexes were immobilized in supercages of NaY. Catalytic studies were performed in liquid phase for the cyclohexene oxidation, at 40 °C, using tert-butyl hydroperoxide (TBHP) as the oxidizing agent. All the prepared catalysts exhibited catalytic activity for the oxidation reaction., União Europeia. Fundo Europeu de Desenvolvimento Regional (FEDER), Fundação para a Ciência e a Tecnologia (FCT) - ref. POCTI/44449/CTA/2002, POCTI-SFA-3-686

This work reports on the application of solar-activated photocatalytic thin films that allow the controlled-release of volatile agents (e.g., insecticides, repellents) from the interior of adsorbed polymeric microcapsules. In order to standardize the tests,a quantification of the inherent controlled-release of a particular volatile agent is determined by gas chromatography coupled to mass spectroscopy, so that an application can be offered to a wide range of supports from various industrial sectors, such as in textiles (clothing, curtains, mosquito nets). This technology takes advantage of the established photocatalytic property of titanium dioxide (TiO2) for the use as an active surface/site to promote the controlled-release of a specific vapor (volatile agentfrom within the aforementioned microcapsules., Portuguese FCT COMPETE scientific programs, with references NANO/NTec-CA/0046/2007 and PTDC/CTM-NAN/119979/2010

The preparation of the (N,N'-diarylacetamidine)rhodium(III) complex in the cavities of zeolite Y is reported. The guest rhodium(III) complex was entrapped in the supercages of zeolite Y as a host by a two-step process in the liquid phase: (I) inclusion of rhodium(III) by ion-exchange in the structure and (II) introduction of N,N'-diarylacetamidine ligand followed by assembly of the complex inside the void space of the zeolite. The neat complex has also been prepared and characterized. The appropriate process selected for the in situ complex synthesis involved using an N,N'-diarylacetamidine ligand : rhodium(III) molar ratio of 4 : 1. Spectroscopic studies (Fourier transform infrared spectroscopy), chemical analyses, surface (X-ray photoelectron spectroscopy, scanning electron microscopy and X-ray diffraction) and cyclic voltammetric studies were used to characterize the new host-guest materials. Analysis of the data of the neat and encapsulated complex show that the coordination of the rhodium(III) ion (as a guest in the host structure) by the nitrogen atoms of the N,N'-diarylacetamidine ligand occurred in a 2 : 1 stoichiometry.