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Reguera E.,Center for Applied Science and Advanced Technology of | Rodriguez-Hernandez J.,Center for Applied Science and Advanced Technology of | Rodriguez-Hernandez J.,University of Habana | Tellez C.,Center for Applied Science and Advanced Technology of | Centeno M.,Center for Applied Science and Advanced Technology of
Zeitschrift fur Physikalische Chemie | Year: 2010

In the research area of molecular magnets for Prussian blue analogues interesting and unusual effects have been observed, particularly for mixed transition metal salts of the hexacyanochromate (III) anion, TA 3-xTB x[Cr(CN)6]2̇yH2O. For single metal salts, T3[Cr(CN)6]2̇yH2O, with T =Mn(2+), Fe(2+), Co(2+), three paramagnetic ions where long range magnetic order is observed, the materials show low stability. The structural change can be envisaged as a flipping of the CN ligand, from T-NhC-Cr-ChN-T to Cr-NhC-T-ChN-Cr. The material containing these metals (Mn, Fe, Co) could be partially stabilized by the incorporation of a second metal that does not form stable hexacyano complexes (Ni, Cu, Zn, Cd). In this contribution such possibility is explored. The role of the porous framework in the material low stability is also discussed. For analog compact solids, TCs[Cr(CN)6], a relatively high stability on aging was observed. The study of the mixed compositions is preceded by a structural characterization of the simple series where the effect of the crystal water removal is also considered. © by Oldenbourg Wissenschaftsverlag, München.


Figueroa-Espi V.,University of Habana | Alvarez-Paneque A.,University of Habana | Torrens M.,University of Habana | Otero-Gonzalez A.J.,University of Habana | And 2 more authors.
Colloids and Surfaces A: Physicochemical and Engineering Aspects | Year: 2011

In this study the potential applications of manganese ferrite (MnFe2O4) nanoparticles for bioanalytical applications are evaluated. These magnetic nanoparticles show peroxidase-like activity similar to that reported for magnetite nanoparticles and peroxidase enzyme. Based on this finding, colloidal suspensions of manganese ferrite were conjugated to an anti-Sticholysin II (StII) monoclonal antibody. The resulting conjugate was then used as a revealing tool in a novel immunoassay for StII detection. From the combined magnetic properties and specific recognition of anti-StII-MnFe2O4 conjugate, Sticholysins were separated from whole aqueous extract of marine anemone obtaining 75% of purity. The results herein discussed illustrate the potential applications of manganese ferrite nanoparticles as bioanalytical tools for immunoassay and protocol for protein separation. © 2011 Elsevier B.V.


Lopez-Abarrategui C.,University of Habana | Figueroa-Espi V.,University of Habana | Reyes-Acosta O.,Center for Genetic Engineer and Biotechnology | Reguera E.,Center for Applied Science and Advanced Technology of | Otero-Gonzalez A.J.,University of Habana
Current Protein and Peptide Science | Year: 2013

Antimicrobial peptides are distributed in all forms of life presenting activity against bacteria, fungi, viruses, parasites and cancer. In spite of the tremendous potential of these molecules, very few of them have been successfully developed into therapeutics. The major problems associated with this new class of antimicrobials are molecule stability, toxicity in host cells and production cost. A novel strategy to overcome these obstacles is conjugation to nanomaterials. Magnetic nanoparticles have been widely studied in biomedicine due to their physicochemical properties. The conjugation of antimicrobial peptides to magnetic nanoparticles could combine the best properties of both, generating an improved antimicrobial nanoparticle. Here we provide an overview and discuss the potential application of magnetic nanoparticles conjugated to antimicrobial peptides in overcoming diseases. © 2013 Bentham Science Publishers.


Avila M.,Center for Applied Science and Advanced Technology of | Rodriguez-Hernandez J.,Center for Applied Science and Advanced Technology of | Rodriguez-Hernandez J.,University of Habana | Lemus-Santana A.A.,Center for Applied Science and Advanced Technology of | Reguera E.,Center for Applied Science and Advanced Technology of
Journal of Physics and Chemistry of Solids | Year: 2011

The cation (A) mobility and structural changes on the water molecules removal in zeolite-like zinc hexacyanometallates series, Zn3A 2[Fe(CN)6]2·xH2O with A=Na, K, Rb and Cs, were studied from X-ray diffraction data recorded for hydrated and anhydrous samples at room temperature and at 77 K. The crystal structure for the anhydrous phases were solved and refined and then compared with those corresponding to their hydrated form. On the water molecules removal the charge balancing cation (A) migrates to favor a stronger interaction with the N ends of the CN bridges where the framework negative charge is located. This cationframework interaction model is supported by the recorded IR spectra for both hydrated and anhydrous samples. The new cation position induces distortion for both the cavity shape and their windows and also leads to cavity volume reduction. This is relevant for the properties of this family of solids as porous materials and their behavior in adsorption and separation processes, among them for hydrogen storage. © 2011 Elsevier Ltd.

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