Nanostructured systems for drug delivery

Drug delivery refers to approaches for transporting drugs in the body, with the objective to achieve site-targeting in the organism. In order to achieve a controlled release of drugs, the use of nanocarriers in drug delivery has been proposed. Among the different types of nanocarriers assayed as drug delivery systems, polymeric micelles have been successful for biomedical applications. Polymeric micelles can be stabilized by crosslinking providing Cross-Linked Polymeric Micelles, in which the preformed micellar assemblies are blocked via covalent bonding. The aims of this research work are the design and synthesis of new amphiphilic block copolymers based on Pluronic F127 with the ability to self-arrange in water forming micelles, which will be photopolymerized in order to obtain cross-linked polymeric micelles, with applications as nanocarriers in drug delivery

Thermosensitive and photopolymerizable hydrogels based on Pluronic F127

Here it is reported the design, synthesis and characterization of new Pluronic® F127 derivatives, with the ability to form thermosensitive and photopolymerizable hydrogels. These active hydrogels undergo a sol-to-gel transition by increasing the temperature in a physiologically important temperature range thus resulting attractive for biomedical applications and drug delivery systems. Pluronic® F127 has been functionalized with photoreactive groups and the obtained derivatives and their precursors have been fully characterized by conventional techniques. Then the aimed compounds have been processed as macroscopically molded hydrogels and as nanostructured hydrogels (nanogels). A highly crosslinked internal structure has been reached by the photopolymerization technique for the thermosensitive macroscopic hydrogels designed to act as cell scaffolds for cartilage repair. Swelling and degradation studies as well as their morphological characterization by SEM have been carried out. Concerning the nanostructured hydrogels (nanogels), after determining its critical micellar concentration and applying a photopolymerization process to fix the nanostructure, they have been characterized by TEM, SEM and DLS. Cell viability assays have been carried out for both types of system, the macroscopic hydrogel and the nanogel

Encapsulación de flavonoles en ciclodextrinas. Efectos en su actividad antioxidante

1. Los tres flavonoles estudiados, miricetina, quercetina y kaempferol, pueden ser complejados en CDs, aumentando su solubilidad acuosa por la formación de complejos 1:1. 2. La complejación de miricetina, quercetina y kaempferol en CDs, provoca una variación en la intensidad de fluorescencia de los 3 flavonoles. En el caso de miricetina y quercetina, la fluorescencia aumenta con la complejación en CDs, mientras que, en el caso de kaempferol, la fluorescencia disminuye como consecuencia de la complejación. 3. La oxidación de miricetina, quercetina y kaempferol por HPR en presencia de H2O2 es inhibida en la medida en que estos compuestos son complejados por CDs, indicando que el flavonol libre, es el único sustrato disponible para la enzima. 4. La variación en la solubilidad, velocidad de oxidación enzimática y espectro de fluorescencia, permite calcular el valor de las constantes de complejación (KC) de los tres flavonoles objeto de estudio con diferentes tipos de CDs. 5. El método enzimático y los estudios de solubilidad nos proporcionan valores reales de las constantes de complejación entre flavonoles y CDs. Sin embargo, el método fluorimétrico infravalora el valor de dichas constantes en los tres flavonoles estudiados. 6. De las CDs estudiadas, HP-β-CDs son las más efectivas en la complejación de miricetina, quercetina y kaempferol, ya que presentan mayor valor de KC, independientemente del método utilizado para el cálculo de la misma. 7. La capacidad antioxidante de miricetina, quercetina y kaempferol aumenta tras su complejación en HP-β-CDs. Cada flavonol complejado presenta aproximadamente el doble de actividad antioxidante que cuando está libre en el medio, indicando que la complejación lo protege frente al ataque por radicales libres.Ciencias de la Alimentació

Effects of Cyclodextrin Type on Vitamin C, Antioxidant Activity, and Sensory Attributes of a Mandarin Juice Enriched with Pomegranate and Goji Berries

The effects of the addition of cyclodextrins (CDs), β-CD, or HP-β-CD (1%), on the protection of antioxidant compounds of mandarin juices enriched with pomegranate extract and goji berries juice, was studied. Juices were prepared and after their thermal treatment (98 ◦C, 30 s) they were stored at 4 ◦C during 75 d. Vitamin C content, CIE L∗a∗b∗ color, antioxidant capacity, retinol equivalents, and sensory properties were studied. Losses on vitamin C were higher (6%) for juices with β-CD than juices with HP-β-CD. Retinol equivalents degradation was lower (3.4%) in juices with HP-β-cyclodextrins than in those treated with β-CD. Lower losses were observed for the instrumental and sensory color intensity in juices with HP-β-CD addition. Finally, the antioxidant capacity was also higher in juices treated with HP-β-CD. Finally, the overall sensory quality of juices with HP-β-CD was the best one after 30 d of cold storage. Even though β-CD addition did not cause any improvement compared with control juice (without CD addition), the benefits of adding HP-β-CD to this particular juice were shown in almost all parameters under study.Ciencias de la Alimentació

The relationship between stress, negative (dark) personality traits, and utilitarian moral decisions

There is a growing evidence that stress affects cognitive and emotional processes underling decision making. However, according some authors, subclinical personality traits of the participants must be also considered in this relation between stress and moral decision. Our study examines whether stress affects moral decision-making according two different subclinical personalities. Forty undergraduate volunteers were previously distributed according their personality traits (Machiavellian; Narcissism and Normal) and randomly assigned to both conditions (stress vs. control). The stress induction was assessed with a self-reported questionnaire and with a measurement of heart rate. All participants performed a moral decision-making task in which every day moral dilemmas were described. The main results suggest that stress group made less utilitarian choices when compared to control group. Although machiavellian and narcissistic participants made more utilitarian decisions; the interaction between stress, personality and moral judgment did not reach significance.   We conclude that stress induction predisposed participants to less utilitarian responses when faced to personal and impersonal moral dilemmas. We also suggested that subclinical personality (particularly narcissism) seems to be less permeable to stress; revealing the same moral utilitarian pattern in both experimental conditions.Abstract: Stress affects the cognitive and emotional processes involved in moral decisions, leading to less utilitarian choices. Our study examines whether specific negative (dark) personality traits – narcissism and Machiavellianism – moderate the impact of stress on moral decision-making. Forty undergraduate volunteers were classified into three trait groups («high Machiavellian», «high narcissistic» and «low negative traits»), randomly assigned to two experimental conditions (stress vs. control) and asked to perform a moral decision task. The main results suggest that participants under acute stress made fewer utilitarian decisions when faced with personal moral decisions compared to participants from the control group and that this effect was partially moderated by negative personality traits. We concluded that acute stress may reduce utilitarian decisions in moral dilemmas, but that negative personality traits seem to attenuate the effect of stress on moral decision-making. Keywords: Moral decision; utilitarianism; negative (dark) personality traits; stress. Relación entre el estrés, los rasgos oscuros de la personalidad y las decisiones morales utilitarias Resumen: El estrés afecta a los procesos cognitivos y emocionales envueltos en a las decisiones morales, conduciendo a elecciones menos utilitarias. Nuestro estudio examina si determinados rasgos oscuros de la personalidad – el narcisismo y el maquiavelismo – moderan el impacto del estrés en la toma de decisiones morales. Cuarenta voluntarios universitarios fueron agrupados en tres categorías de rasgos («alto maquiavelismo», «alto narcisismo» y «bajos rasgos negativos»), asignados aleatoriamente a dos condiciones (estrés vs. control) y se les pidió que completasen una tarea de decisión moral. Los resultados principales sugieren que los participantes, bajo situaciones de estrés agudo, tomaron menos decisiones morales personales utilitarias en comparación con los participantes del grupo de control y que este efecto estuvo, parcialmente, moderado por los rasgos oscuros de personalidad. Concluimos que el estrés agudo parece reducir la toma de decisiones utilitarias en los dilemas morales, pero los rasgos oscuros de la personalidad pueden atenuar este efecto del estrés. Palabras clave: Decisión moral; utilitarismo; rasgos oscuros de personalidad; estrés

Splitting of separatrices in Hamiltonian systems and symplectic maps

Poincar\'e, Melnikov and Arnol'd introduced the standard method for measuring the splitting of separatrices of Hamiltonian systems. It is based on the study of the zeros of the so-called Melnikov integral, a vectorial function for three or more degrees of freedom, that gives the first-order behavior. In the most interesting cases, it turns out that the splitting is exponentially small with respect of the parameter of the perturbation, and that means that the remainder has to be bounded very carefully. The mechanism for obtaining rigorously this exponentially small splitting for the one and a half degrees of freedom Hamiltonians is reviewed, and the main ideas for its generalization to more degrees of freedom are presented. Concerning symplectic maps, the Melnikov function is not an integral anymore, but an infinite sum. Nevertheless, for meromorphic perturbations of $2D$-area preserving maps, the Melnikov function turns out to be an elliptic function, and moreover can be evaluated via residues. Furthermore, general results on non-integrability can be provided. For instance, the elliptic billiard turns out to be non-integrable when perturbed by any non-trivial entire perturbation. For more degrees of freedom, using variational arguments, the Melnikov vectorial function for a symplectic map can be deduced from a scalar function (the Melnikov potential), and the splitting of separatrices associated to hyperbolic points can also be easily detected in several situations, for instance for generalized standard maps

The tropical caprellid amphipod Paracaprella pusilla: a new alien crustacean in the Mediterranean Sea

Paracaprella pusilla Mayer (Fauna und Flora des Golfes von Neapel 17:1–55, 1890), originally described from Brazil, is one of the most abundant caprellid amphipod species in tropical and subtropical seas around the world. During a survey of caprellid amphipods from marinas along the Balearic Island (Western Mediterranean Sea) carried out between November 2011 and August 2012, we found two established populations of P. pusilla in Mallorca and Ibiza, respectively. So far, its occurrence in European waters was reported only from southwestern Spain in 2010. This record represents a northward range expansion of the species’ distribution, which is found for the first time in the Mediterranean. This is also the first record of the genus Paracaprella in the Mediterranean Sea. The most probable introduction vector was ship fouling. We also found the invasive caprellid Caprella scaura Templeton (Trans Entomol Soc Lond 1:185–198, 1836) in Mallorca and Menorca, which is recorded for the first time in the Balearic Islands, confirming its rapid expansion along the Mediterranean. When comparing reproductive traits between both alien species, we found that P. pusilla has a higher fecundity than C. scaura for the same female size. Taking into account this evidence, the species may be expected to appear in other Mediterranean and adjacent areas.Ministerio de Economía y Competitividad de España y fondos FEDER de la Unión Europea. CGL2011-707Consejería de Economía, Innovación, Ciencia y Empleo de la Junta de Andalucía. P11-RNM-704