Suchergebnisse

"This is the peer reviewed version of the following article: Oroval, Mar, Paula Díez, Elena Aznar, Carmen Coll, María Dolores Marcos, Félix Sancenón, Reynaldo Villalonga, and Ramón Martínez-Máñez. 2016. Self-Regulated Glucose-Sensitive Neoglycoenzyme-Capped Mesoporous Silica Nanoparticles for Insulin Delivery. Chemistry - A European Journal 23 (6). Wiley: 1353 60. doi:10.1002/chem.201604104, which has been published in final form at https://doi.org/10.1002/chem.201604104. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving." ; [EN] We describe herein the preparation of glucose-sensitive capped mesoporous silica nanoparticles for insulin delivery. The new material consists of an expanded-pore nanometric silica support grafted with 1-propyl-1-H-benzimidazole groups, loaded with fluorescein isothiocyanate-labeled insulin (FITC-Ins) and capped by the formation of inclusion complexes between cyclodextrin-modified glucose oxidase (CD-GOx) and the benzimidazole groups grafted on the mesoporous support. Insulin delivery from the gated material in simulated blood plasma was assessed upon addition of glucose. Glucose is transformed by GOx into gluconic acid, which promoted the dethreading of the benzimidazole-CD-GOx inclusion complexes, allowing cargo release. Small quantities of this support would be needed to release the amount of insulin necessary to decrease diabetic blood glucose concentrations to regular levels. ; The authors thank the Spanish Government (projects CTQ2011-24355, MAT2015-64139-C4-1-R, CTQ2014-58989-P, and AGL2015-70235-C2-2-R (MINECO/FEDER)) and the Generalitat Valenciana (project PROMETEOII/2014/047) for support. M.O. thanks the Universitat Politecnica de Valencia for her FPI grant. P.D. thanks the Ministerio de Economia y Competitividad for her FPI grant (BES-2012-054066). C.C. thanks the Generalitat Valenciana for her postdoctoral contract VALi+D. ; Oroval, M.; Díez, P.; Aznar, E.; Coll Merino, MC.; Marcos Martínez, MD.; Sancenón ...

Abstract In this study, we explored the biocompatibility of Au nanoparticles (NPs) capped with peptide-biphenyl hybrid (PBH) ligands containing glycine (Gly), cysteine (Cys), tyrosine (Tyr), tryptophan (Trp) and methionine (Met) amino acids in the human hepatocellular carcinoma cell line Hep G2. Five AuNPs, Au[(Gly-Tyr-Met)2B], Au[(Gly-Trp-Met)2B], Au[(Met)2B], Au[(Gly-Tyr-TrCys)2B] and Au[(TrCys)2B], were synthesised. Physico-chemical and cytotoxic properties were thoroughly studied. Transmission electron micrographs showed isolated near-spherical nanoparticles with diameters of 1.5, 1.6, 2.3, 1.8 and 2.3 nm, respectively. Dynamic light scattering evidenced the high stability of suspensions in Milli-Q water and culture medium, particularly when supplemented with serum, showing in all cases a tendency to form agglomerates with diameters approximately 200 nm. In the cytotoxicity studies, interference caused by AuNPs with some typical cytotoxicity assays was demonstrated; thus, only data obtained from the resazurin based assay were used. After 48-h incubation, only concentrations ≥50 μg/ml exhibited cytotoxicity. Such doses were also responsible for an increase in reactive oxygen species (ROS). Some differences were observed among the studied NPs. Of particular importance is the AuNPs capped with the PBH ligand (Gly-Tyr-TrCys)2B showing remarkable stability in culture medium, even in the absence of serum. Moreover, these AuNPs have unique biological effects on Hep G2 cells while showing low toxicity. The production of ROS along with supporting optical microscopy images suggests cellular interaction/uptake of these particular AuNPs. Future research efforts should further test this hypothesis, as such interaction/uptake is highly relevant in drug delivery systems. ; This research was performed under the Environmental ChemOinformatics (ECO) Marie Curie Initial Training Network (ITN) programme, funded by the Seventh Research Framework Programme (FP7) of the European Union (238701). We also thank Mapfre research grants 2010, the Spanish Ministry of Economy and Competitiveness (MINECO project CTQ 2010–19295) and the Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (Project AT 2011–001) for financial support. ; Peer Reviewed

[EN] Excessive apoptotic cell death is at the origin of several pathologies, such as degenerative disorders, stroke or ischemia-reperfusion damage. In this context, strategies to improve inhibition of apoptosis and other types of cell death are of interest and may represent a pharmacological opportunity for the treatment of cell-death-related disorders. In this scenario new peptide-containing delivery systems (solids S1-P1and S1-P2) are described based on meso-porous silica nanoparticles (MSNs) loaded with a dye and capped with the KKGDEVDKKARDEVDK (P1) peptide that contains two repeats of the DEVD target sequence that are selectively hydrolyzed by caspase3 (C3). This enzyme plays a central role in the execution-phase of apoptosis. HeLa cells electroporated with S1 P1are able to deliver the cargo in the presence of staurosporin (STS), which induces apoptosis with the consequent activation of the cytoplasmic C3 enzyme. Moreover, the nanoparticles S1-P2,containing both a cell-penetrating TAT peptide and P1 also entered in HeLa cells and delivered the cargo preferentially in cells treated with the apoptosis inducer cisplatin. ; We thank the Spanish Government (Project MAT2012-38429-C04 and SAF2010-15512) and the Generalitat Valenciana (PROMETEOII/2014/061) for support. C.T. is grateful to the Spanish Ministry of Science and Innovation for her PhD fellowship. L.M. thanks the Generalitat Valenciana (VALI+D program), Nice city council ("Aides Individuelles aux Jeunes Chercheurs - 2011") and Fondation de la Recherche Medicale for her postdoctoral contracts. C.C. thanks the Generalitat Valenciana for their postdoctoral contract VALI+D. We thank the confocal microscopy service, Alberto Hernandez from CIPF confocal microscopy service for their technical support. ; De La Torre Paredes, C.; Mondragón Martínez, L.; Coll Merino, MC.; García-Fernández, A.; Sancenón Galarza, F.; Martínez-Máñez, R.; Amorós, P. (2015). Caspase 3 Targeted Cargo Delivery in Apoptotic Cells Using Capped Mesoporous Silica Nanoparticles. Chemistry - A ...

Trapped: Mesoporous silica nanoparticles were loaded with a fluorescent guest and functionalized with octadecyltrimethoxysilane. The alkyl chains interact with paraffins, which build a hydrophobic layer around the particle (see picture). Upon melting of the paraffin, the guest molecule is released, as demonstrated in cells for the guest doxorubicin. The release temperature can be tuned by choosing an appropriate paraffin. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. ; Financial support from the Spanish Government (projects MAT2009-14564-C04-01 and SAF2010-15512) and the Generalitat Valenciana (projects PROMETEO/2009/016 and PROMETEO/2010/005) is gratefully acknowledged. L. M. thanks the Generalitat Valenciana for a VALi + d postdoctoral contract. We thank UPV electron microscopy and CIPF confocal microscopy services for technical support. ; Aznar Gimeno, E.; Mondragón Martínez, L.; Ros-Lis, JV.; Sancenón Galarza, F.; Marcos Martínez, MD.; Martínez Mañez, R.; Soto Camino, J. (2011). Finely tuned temperature-controlled cargo release using paraffin-capped mesoporous silica nanoparticles. Angewandte Chemie International Edition. (50):11172-11175. https://doi.org/10.1002/anie.201102756 ; S ; 11172 ; 11175 ; 50

[EN] Trapped: Mesoporous silica nanoparticles were loaded with a fluorescent guest and functionalized with octadecyltrimethoxysilane. The alkyl chains interact with paraffins, which build a hydrophobic layer around the particle (see picture). Upon melting of the paraffin, the guest molecule is released, as demonstrated in cells for the guest doxorubicin. The release temperature can be tuned by choosing an appropriate paraffin. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. ; Financial support from the Spanish Government (projects MAT2009-14564-C04-01 and SAF2010-15512) and the Generalitat Valenciana (projects PROMETEO/2009/016 and PROMETEO/2010/005) is gratefully acknowledged. L.M. thanks the Generalitat Valenciana for a VALi+d postdoctoral contract. We thank UPV electron microscopy and CIPF confocal microscopy services for technical support. ; Aznar Gimeno, E.; Mondragón Martínez, L.; Ros-Lis, JV.; Sancenón Galarza, F.; Marcos Martínez, MD.; Martínez Mañez, R.; Soto Camino, J. (2011). Finely Tuned Temperature-Controlled Cargo Release Using Paraffin-Capped Mesoporous Silica Nanoparticles. ANGEW CHEM. 123(47):11368-11371. https://doi.org/10.1002/ange.201102756 ; S ; 11368 ; 11371 ; 123 ; 47

Brown-headed Cowbird (Molothrus ater) parasitism is thought to be partly influenced by density of the host species, although tests of host density are relatively rare. We examined parasitism rates relative to the density of individual host species and densities of coexisting host species. We monitored 392 nests among coexisting host species and measured their densities among six habitats on Fort Hood Military Reservation, Texas during 1991-1992 to test the hypothesis that coexisting species affect parasitism rates in the endangered Black-capped Vireo (Vireo atricapillus). Black-capped Vireos and White-eyed Vireos (V. griseus) suffered three to four times higher cowbird parasitism than Northern Cardinals (Cardinalis cardinalis) or Painted Buntings (Passerina ciris). After controlling for removal of female cowbirds, which has been conducted on the study site since 1988, parasitism rates in Black-capped Vireos were positively correlated with cumulative host density in general, and Northern Cardinal density in particular. Only density of Northern Cardinals explained a significant amount of variation in parasitism rates in Black-capped Vireos among sites. We suggest that cowbirds may be attracted to conspicuous species, such as cardinals, and that high densities of such species may negatively affect coexisting species by increasing probabilities of being parasitized. Vireo nests were characterized by less nest concealment, greater canopy cover, and more stems than other species. However nest site and vegetation characteristics did not differ between parasitized and unparasitized nests for any species, suggesting habitat was unimportant to parasitism.

[EN] A hybrid capped mesoporous material, which was selectively opened in the presence of Tetryl and TNT, has been synthesised and used for the fluorogenic recognition of these nitroaromatic explosives. ; Financial support from the Spanish Government (project MAT2012-38429-C04-01) and the Generalitat Valencia (project PROMETEO/2009/016) is gratefully acknowledged. Y.S. and E.P. are grateful to the Spanish Ministry of Science and Innovation for their grants. A. A. also thanks the Generalitat Valenciana for his Santiago Grisolia fellowship. ; Salinas Soler, Y.; Agostini, A.; Pérez Esteve, E.; Martínez Mañez, R.; Sancenón Galarza, F.; Marcos Martínez, MD.; Soto Camino, J. (2013). Fluorogenic detection of Tetryl and TNT explosives using nanoscopic-capped mesoporous hybrid materials. Journal of Materials Chemistry. 1(11):3561-3564. https://doi.org/10.1039/C3TA01438J ; S ; 3561 ; 3564 ; 1 ; 11 ; Singh, S. (2007). Sensors—An effective approach for the detection of explosives. Journal of Hazardous Materials, 144(1-2), 15-28. doi:10.1016/j.jhazmat.2007.02.018 ; Schulte-Ladbeck, R., Vogel, M., & Karst, U. (2006). Recent methods for the determination of peroxide-based explosives. Analytical and Bioanalytical Chemistry, 386(3), 559-565. doi:10.1007/s00216-006-0579-y ; Smith, R. G., D'Souza, N., & Nicklin, S. (2008). A review of biosensors and biologically-inspired systems for explosives detection. The Analyst, 133(5), 571. doi:10.1039/b717933m ; Moore, D. S. (2004). Instrumentation for trace detection of high explosives. Review of Scientific Instruments, 75(8), 2499-2512. doi:10.1063/1.1771493 ; H�kansson, K., Coorey, R. V., Zubarev, R. A., Talrose, V. L., & H�kansson, P. (2000). Low-mass ions observed in plasma desorption mass spectrometry of high explosives. Journal of Mass Spectrometry, 35(3), 337-346. doi:10.1002/(sici)1096-9888(200003)35:3 337::aid-jms940>3.0.co;2-7 ; Wallis, E., Griffin, T. M., Popkie, Jr., N., Eagan, M. A., McAtee, R. F., Vrazel, D., & McKinly, J. (2005). Instrument response ...

et al. ; We report on the effect of cap layer material on the magnetic properties and aging of the Fe-NW (nanowire) arrays grown on oxidized vicinal Si (111) templates using atomic terrace low angle shadowing technique. We find that the Fe-NW arrays capped with metallic (Ag) layers do not show any sign of degradation with aging, whereas NW arrays capped with insulating dielectric (MgO) layers show degradation of the saturation magnetization and an out-of-plane unidirectional anisotropy. We find that this out-of-plane unidirectional anisotropy competes with the shape anisotropy which is still the dominant anisotropy. The origin of this additional anisotropy is explained on the basis of oxidation of Fe due to the presence of MgO that leads to the formation of an oxide interlayer. This oxide interlayer forms at the expense of NW materials, leading to reduction in the thickness of some of the Fe-NWs within the array, and orients their magnetic moments out-of-plane. The reduction in NW thickness and the presence of Fe-O interlayer facilitates stabilization of this anisotropy. Our model is supported by x-ray absorption spectroscopy studies performed as a function of aging, which suggests that the oxide interlayer thickness increases with aging. © 2013 AIP Publishing LLC. ; Work supported by the Science Foundation Ireland (SFI) under Contract No. 06/IN.1/I91, ERA-Net NANOWAVE program, the Irish Government's Program (ISPIRE) for Research in Third Level Institutions, Cycle 4, National Development Plan 2007-2013, the Spanish Ministerio de Ciencia y Innovación (EUI2008-03884 and PTA2008-1108-I), Agència de Gestió d'Ajuts Universitaris i de Recerca (2009 SGR 695), and Nanoaracat. ; Peer Reviewed

[EN] Aptamers have been used as recognition elements for several molecules due to their great affinity and selectivity. Additionally, mesoporous nanomaterials have demonstrated great potential in sensing applications. Based on these concepts, we report herein the use of two aptamer¿capped mesoporous silica materials for the selective detection of ochratoxin¿A (OTA). A specific aptamer for OTA was used to block the pores of rhodamine¿B¿loaded mesoporous silica nanoparticles. Two solids were prepared in which the aptamer capped the porous scaffolds by using a covalent or electrostatic approach. Whereas the prepared materials remained capped in water, dye delivery was selectively observed in the presence of OTA. The protocol showed excellent analytical performance in terms of sensitivity (limit of detection: 0.5¿0.05¿nm), reproducibility, and selectivity. Moreover, the aptasensors were tested for OTA detection in commercial foodstuff matrices, which demonstrated their potential applicability in real samples ; We thank the Spanish Government (projects MAT2015-64139-C4-1-R and AGL2015-70235-C2-2-R (MINECO/FEDER)) and the Generalitat Valenciana (project PROMETEOII/2014/047) for support. A.R. thanks UPV for her predoctoral fellowship. S.S. thanks the Instituto de Salud Carlos III and the European Social Fund for the financial support "Sara Borrell" (CD16/000237). A.B. thanks the Spanish Government for financial support by the "Juan de la Cierva-Incorporacion" (IJCI-2014-21534). The authors also thank the Electron Microscopy Service at UPV for support. ; Ribes, À.; Santiago Felipe, S.; Bernardos Bau, A.; Marcos Martínez, MD.; Pardo Vicente, MT.; Sancenón Galarza, F.; Martínez-Máñez, R. (2017). Two New Fluorogenic Aptasensors Based on Capped Mesoporous Silica Nanoparticles to Detect Ochratoxin A. ChemistryOpen. 6(5):653-659. https://doi.org/10.1002/open.201700106 ; S ; 653 ; 659 ; 6 ; 5