Fluoride-promoted carbonylation polymerization: a facile step-growth technique to polycarbonates.

Fluoride-Promoted Carbonylation (FPC) polymerization is herein presented as a novel catalytic polymerization methodology that complements ROP and unlocks a greater synthetic window to advanced polycarbonates. The overall two-step strategy is facile, robust and capitalizes on the synthesis and step-growth polymerization of bis-carbonylimidazolide and diol monomers of 1,3- or higher configurations. Cesium fluoride (CsF) is identified as an efficient catalyst and the bis-carbonylimidazolide monomers are synthesized as bench-stable white solids, easily obtained on 50-100 g scales from their parent diols using cheap commercial 1,1'-carbonyldiimidazole (CDI) as activating reagent. The FPC polymerization works well in both solution and bulk, does not require any stoichiometric additives or complex settings and produces only imidazole as a relatively low-toxicity by-product. As a proof-of-concept using only four diol building-blocks, FPC methodology enabled the synthesis of a unique library of polycarbonates covering (i) rigid, flexible and reactive PC backbones, (ii) molecular weights 5-20 kg mol-1, (iii) dispersities of 1.3-2.9 and (iv) a wide span of glass transition temperatures, from -45 up to 169 °C.

In vitro evaluation of the effectiveness of new water-stable cationic carbosilane dendrimers against Acanthamoeba castellanii UAH-T17c3 trophozoites.

Acanthamoeba is one of the most common free-living amoebas which is widespread in the environment and can infect humans, causing diseases such as keratitis and encephalitis. In this paper we examine for the first time the amebicidal activity of the family of cationic dendrimers nG-[Si{(CH(2))(3)N(+)(Me)(Et)(CH(2))(2)NMe(3) (+)}2I(-)]( x ) (where n denotes the generations: zero (n = 0, x = 1), first (n = 1, x = 4), and second (n = 2, x = 8); for simplicity, they were named as 0G-CNN2, 1G-CNN8, and 2G-CNN16, respectively) against Acanthamoeba castellanii UAH-T17c3 trophozoites. In order to test the amebicidal activity, we cultured the strain A. castellanii UAH-T17c3 in PYG-Bactocasitone medium and later, we treated it with different concentrations of these dendrimers and monitored the effects and damage by optical count, flow cytometry, and scanning electron microscopy. The results showed that all the nanosystems assayed had a strong amebicidal activity. The dendrimer 1G-CNN8 was the most effective against the amoeba. In the morphology of treated throphozoites of A. castellanii UAH-T17c3 analyzed by light and scanning electron microscopy techniques, morphological changes were evident in amoeba cells, such as loss of pseudopodia, ectoplasm increase, roundness, and cellular lysis. Furthermore, flow cytometry results showed alterations in cell granularity, which was dose-time dependent. In conclusion, this family of cationic carbosilane dendrimers has a strong amebicidal activity against the trophozoites of A. castellanii UAH-T17c3 in vitro. They could potentially become new agents significant to the development of new amebicidal compounds for prevention and therapy of Acanthamoeba infections.

In vitro studies of water-stable cationic carbosilane dendrimers as delivery vehicles for gene therapy against HIV and hepatocarcinoma.

Here we present a synthetic procedure for water-stable carbosilane dendrimers containing ammonium groups at the periphery of type Gn-{[Si(CH2)3N+(Me)(Et)CH2CH2N+Me3]x (CF3SO3 -)y} which have been used as non-viral vectors for transfecting different types of nucleic acids against two different medical problems, HIV and hepatocarcinoma. These systems have shown to be non-toxic in both PBMC and HepG2 cell lines under the experimental conditions and are able to form nanoconjugates with nucleic acids perfectly stable over time and in a wide range of pH values, which leads to the conclusion that the interaction between dendrimer and nucleic acid is very strong. In addition, a high degree of transfection using these nanoconjugates has been observed, ranging from 70-90% depending on the generation and in the particular case of PBMC transfection with anti-HIV oligonucleotides. However, besides of the good properties shown by the dendrimers here prepared as transfecting agents, only moderate effect was observed in functional experiments for hepatocarcinoma, as a result of the strong interaction between dendrimer and nucleic acid. Nevertheless, it is important to mention that an IRS-4 knock-down of 40% in HepG2 achieves an analogous degree of cell sensitization to cancer treatment, which may represent a major advance in the hepatocarcinoma treatment when appropriate dendrimers as transfection agents are used.

Antiviral properties against HIV of water soluble copper carbosilane dendrimers and their EPR characterization.

We describe here the use of anionic carbosilane dendrimers to obtain new copper complexes. UV-Vis and a computer aided analysis of the EPR spectra provided information about the coordination modes of copper depending on the nature of the dendrimer and about the geometry and structure of the complexes in solution. Some of these metallo-dendrimers have been tested "in vitro" as antiviral compounds in the inhibition of HIV infection in pre and post-infection treatment.

Tortícolis congénita: incidencia y actuación fisioterápica en neonatos con contractura en el esternocleidomastoideo / Congenital torticollis: Incidence and physiotherapeutic performance in newborns with contracture of sternocleidomastoid

Con el objeto de diferenciar casos de Tortícolis congénita por hematoma o por contractura en el ECM, tanto en su evaluación como en su tratamiento, hemos realizado este estudio en una muestra de 45 neonatos de una Zona Básica de Atención Primaria de Badajoz durante el primer año de vida. Se pretende demostrar la importancia en todos los casos del tratamiento precoz y seguimiento, precedido de una buena evaluación.Antes de iniciar el método de tratamiento realizamos una evaluación del desarrollo psicomotor del niño teniendo en cuenta la Actividad Refleja y los Hitos en las Etapas del Desarrollo. Destacar además la valoración de la musculatura tónica del cuello, tronco y extremidades para así hacer un tratamiento más diferenciado. La metodología empleada ha sido Tratamiento Neurodesarrollante de Bobath, y Reequilibración Tónica, así como enseñanza a los padres de medidas paleativas durante este primer año de vida. Los resultados más significativos han sido una mayor incidencia de contractura que de hematoma, más incidencia en niños que en niñas, mejores resultados obtenidos cuanto antes nos fueron derivados, siendo la edad media de derivación de 2,5 meses, así como mayor presencia de plagiocefalia como patología asociada (AU)