A novel hybrid nanofibrous strategy to target progenitor cells for cost-effective in situ angiogenesis.

Although the impact of composites based on Ti-doped calcium phosphate glasses is low compared with that of bioglass, they have been already shown to possess great potential for bone tissue engineering. Composites made of polylactic acid (PLA) and a microparticle glass of 5TiO2-44.5CaO-44.5P2O5-6Na2O (G5) molar ratio have already demonstrated in situ osteo- and angiogenesis-triggering abilities. As many of the hybrid materials currently developed usually promote osteogenesis but still lack the ability to induce vascularization, a G5/PLA combination is a cost-effective option for obtaining new instructive scaffolds. In this study, nanostructured PLA-ORMOGLASS (organically modified glass) fibers were produced by electrospinning, in order to fabricate extra-cellular matrix (ECM)-like substrates that simultaneously promote bone formation and vascularization. Physical-chemical and surface characterization and tensile tests demonstrated that the obtained scaffolds exhibited homogeneous morphology, higher hydrophilicity and enhanced mechanical properties than pure PLA. In vitro assays with rat mesenchymal stem cells (rMSCs) and rat endothelial progenitor cells (rEPCs) also showed that rMSCs attached and proliferated on the materials influenced by the calcium content in the environment. In vivo assays showed that hybrid composite PLA-ORMOGLASS fibers were able to promote the formation of blood vessels. Thus, these novel fibers are a valid option for the design of functional materials for tissue engineering applications.

Towards 4th generation biomaterials: a covalent hybrid polymer-ormoglass architecture.

Hybrid materials are being extensively investigated with the aim of mimicking the ECM microenvironment to develop effective solutions for bone tissue engineering. However, the common drawbacks of a hybrid material are the lack of interactions between the scaffold's constituents and the masking of its bioactive phase. Conventional hybrids often degrade in a non-homogeneous manner and the biological response is far from optimal. We have developed a novel material with strong interactions between constituents. The bioactive phase is directly exposed on its surface mimicking the structure of the ECM of bone. Here, polylactic acid electrospun fibers have been successfully and reproducibly coated with a bioactive organically modified glass (ormoglass, Si-Ca-P2 system) covalently. In comparison with the pure polymeric mats, the fibers obtained showed improved hydrophilicity and mechanical properties, bioactive ion release, exhibited a nanoroughness and enabled good cell adhesion and spreading after just one day of culture (rMSCs and rEPCs). The fibers were coated with different ormoglass compositions to tailor their surface properties (roughness, stiffness, and morphology) by modifying the experimental parameters. Knowing that cells modulate their behavior according to the exposed physical and chemical signals, the development of this instructive material is a valuable advance in the design of functional regenerative biomaterials.

Inhibitory effects of curcumin on dengue virus type 2-infected cells in vitro.

Curcumin, a traditional Chinese and Indian treatment for many diseases, has recently been found to alter the in vitro infection processes of various viruses, including hepatitis C virus, human immunodeficiency virus, coxsackievirus, and Japanese encephalitis virus. The present study evaluated the cellular effects of curcumin in an in vitro (cellular) infection model of dengue virus. Within a dose range of 10 to 30 µM and a treatment period of 24 hours, the cytotoxicity of curcumin was low, as determined by MTT assays. Cells infected with dengue virus type 2 at a multiplicity of infection of 5 were treated with various concentrations of curcumin or the proteasome inhibitor MG132. Plaque assays, immunofluorescence analysis, western blots, and in-cell western assays were then performed. Treatment with 10, 15, and 20 µM curcumin decreased the number of plaques produced, caused an intracellular accumulation of viral proteins, and increased the level of Lys48 ubiquitin-conjugated proteins. At 20 µM curcumin, changes in cell and nuclear morphology and alterations in the actin cytoskeleton were also observed. Treatment with MG132 also reduced plaque production. These results show that curcumin can interfere with the infection processes of dengue virus and that this interference may not occur through direct effects on viral particle production but may result from curcumin's effects on various cellular systems such as the cytoskeleton, the ubiquitin-proteasome system, or the apoptosis process.

Obtención de anticuerpos monoclonales de ratón contra proteasa de cisteína 5 recombinante de Entamoeba histolytica / Production of monoclonal antibodies against cysteine protease 5 of Entamoeba histolytica

Objetivo. Obtener anticuerpos monoclonales de ratón contra la proteasas de cisteína 5 (EhCP5) de Entamoeba histolytica. Materiales y métodos. Se inmunizaron ratones BALB/c por vía intraperitoneal con adyuvante de Freund completo e incompleto con la proteína recombinante EhCP5 obtenida a partir del cultivo de E.coli DH5α trasfectada con el vector recombinante pJC45 que expresa dicha proteína. Se seleccionó el animal con mejor respuesta de anticuerpos. Al cual se le extrajo su bazo como fuente de linfocitos B, los cuales se fusionaron utilizando PEG con células de mieloma de ratón SP2-0/Ag14. Se procedió a selección de los hibridomas y a la evaluación de los sobrenadantes de las colonias que crecieron a los 7 días mediante ELISA. Los hibridomas con valores más altos de anticuerpos específicos contra la proteína EhCP5r se seleccionaron, y los clones obtenidos por diluciones limitantes fueron expandidos. Resultados. A partir de un clon secretor estable se purifico el anticuerpo monoclonal anti EhCP5r del isotipo IgG1 por cromatografía de afinidad con proteína G. Los clones fueron expandidos in vivo ein vitro. Con el anticuerpo purificado se diseñaron tres sistemas de captura para evaluar la aplicabilidad del anticuerpo monoclonal anti EhCP5r como método inmunodiagnóstico. Conclusiones. Se logro la producción de un anticuerpo monoclonal específico contra EhCP5r que permite diferenciar Entamoeba histolytica de Entamoeba dispar.

Objective. Obtain mouse monoclonal antibodies against cysteine proteases 5 (EhCP5) of Entamoeba histolytica. Materials and methods. BALB/c mice were immunized intraperitoneally with complete and incomplete Freund adjuvant EhCP5 with the recombinant EhCP5 protein obtained from E.coli DH5α culture transfected with the recombinant vector pJC45 that expresses said protein. The animal with the best antibody response was selected. Its spleen was extracted as a source of B-lymphocytes, which were merged using PEG miceSP2-0/Ag14 myeloma cells. The team proceeded to undergo the selection of the hybridomas and the evaluation of the supernatants of the colonies that grew after 7 days by ELISA. The hybridomas with higher values of specific antibodies against the protein EhCP5r were selected, and clones obtained by limiting dilution were expanded Results. With the use of a stable secreting clone the monoclonal antibody anti EhCP5r IgG1 isotype was purified by affinity chromatography with protein G. The clones were expanded in vivo and in vitro. Three capture systems were designed with the purified antibody to assess the applicability of the monoclonal antibody anti EhCP5r as an immunodiagnostic method. Conclusions. The production of a specific monoclonal antibody against EhCP5r was achieved to differentiate Entamoeba histolytica from Entamoeba dispar.

Injectable and fast resorbable calcium phosphate cement for body-setting bone grafts.

In this work a calcium phosphate (CPC)/polymer blend was developed with the advantage of being moldable and capable of in situ setting to form calcium deficient hydroxyapatite under physiological conditions in an aqueous environment at body temperature. The CPC paste consists in a mix of R cement, glycerol as a liquid phase carrier and a biodegradable hydrogel such as Polyvinyl alcohol, which acts as a binder. Microstructure and mechanical analysis shows that the CPC blend can be used as an injectable implant for low loaded applications and fast adsorption requirements. The storage for commercial distribution was also evaluated and the properties of the materials obtained do not significantly change during storage at -18 degrees C.

Inmunogenicidad de la proteína recombinante asp1r de Ancylostoma caninum en un modelo murino / Immunogenicity of the protein recombinant asp1r of a caninum in a murine model

Objetivo. Construir un plásmido recombinante que exprese la proteína ASP1r de Ancylostoma caninum y evaluar su capacidad inmunogénica en un modelo murino. Materiales y métodos. Se realizó extracción de ARN de parásitos adultos de Ancylostoma caninum, se amplificó por RT –PCR el gen de la proteína ASP1. Este gen fue insertado en el vector pcDNA3. El inserto fue digerido con Bamh1 y EcoR1 y clonado direccionalmente. Posteriormente, se llevó a cabo transformación y selección de las células de E. coli DH5a competentes con el producto de la ligación. Se realizó un tamizaje por PCR confirmando la presencia del gen ASP1. El vector pcDNA3-ASP1 fue administrado vía intraglandular en la parotida e intramuscular enratones Balb/c. En estos animales se les realizó determinación de anticuerpos en suero y saliva mediante las técnicas de ELISA e inmunohistoquímica. Resultados. Se determinó que el plásmido pcDNA3-ASP1 fue incorporado y expresado células E. coli DH5a. Este plásmido recombinante indujo la producción de anticuerpos Anti-ASP1 específicos en ratones Balb/c. Conclusiones. Se logró demostrar que la utilización de pcDNA3-ASP1 no produjo reacciones desfavorables en ratones Balb/c, además indujo respuesta humoral contra la proteína pcDNA3- ASP1 de excreción/secreción de Ancylostoma caninum en ratones.

Biomaterials in orthopaedics.

At present, strong requirements in orthopaedics are still to be met, both in bone and joint substitution and in the repair and regeneration of bone defects. In this framework, tremendous advances in the biomaterials field have been made in the last 50 years where materials intended for biomedical purposes have evolved through three different generations, namely first generation (bioinert materials), second generation (bioactive and biodegradable materials) and third generation (materials designed to stimulate specific responses at the molecular level). In this review, the evolution of different metals, ceramics and polymers most commonly used in orthopaedic applications is discussed, as well as the different approaches used to fulfil the challenges faced by this medical field.

[Vegetarian diets; effect on health]. / Dietas vegetarianas; repercusión sobre la salud.

Vegetarian diets are those diets mainly based on the consumption of vegetable product, but that also permit consumption of eggs and milk. The American Dietetic Association made a declaration on these vegetarian diets in which they stated that <>. Some studies have shown beneficial results in obesity, cancer, Parkinson disease, hypertension, type 2 diabetes mellitus and urinary stones, compared with the omnivorous. The possible theoretical benefits in some diseases has been seen in the medical practice (diabetes mellitus, obesity, cardiovascular risk). However more studies are needed in the case of Parkinson's disease and rheumatoid arthritis.

An experimental and theoretical study of the basicity of tetra-tert-butyltetrahedrane.

The gas-phase basicity (GB) of tetra-tert-butyltetrahedrane (tBu4THD) was determined by FT-ICR mass spectrometry and comparison with reference compounds of known basicity. Its GB, 1035+/-10 kJ x mol(-1), makes tetra-tert-butyltetrahedrane one of the strongest bases reported so far. Ab initio calculations [B3LYP/6-31G(d) and B3LYP/6-311 + G(d,p)//6-31G(d)] have been carried out in order to compare the high experimental basicity of tBu4THD with that estimated theoretically. Both B3LYP/6-31G(d) and QCISD(T) calculations were used to determine the reaction path which connects the initial tetrahedrane-ammonium complex with the final products, protonated cyclobutadiene (CBDH+) and ammonia.

Organic Thermochemistry at High ab Initio Levels. 3. A G3 Study of Cyclic Saturated and Unsaturated Hydrocarbons (Including Aromatics).

With the purpose of exploring the reliability of the enthalpies of formation calculated using the G3 method, we have examined a series of saturated and unsaturated alicyclic hydrocarbons varying the size and the number of formal double bonds in the molecule. Heats of formation have been calculated at the G3 level through both atomization reactions and bond separation isodesmic reactions, and comparisons with experimental values and with values previously calculated at the G2(MP2) and G2 levels have been made. The quality of the G3-calculated enthalpies of formation using atomization reactions is comparable to that obtained at the G2 level using bond separation reactions, whereas G3 calculations are two to three times faster than G2 calculations.