Facile Obtainment of Fluorescent PEG Hydrogels Bearing Pyrene Groups by Frontal Polymerization.

Frontal polymerization (FP) was used to prepare poly(ethylene glycol) methyl ether acrylate (PEGMA) fluorescent polymer hydrogels containing pyrenebutyl pendant groups as fluorescent probes. The polymerization procedure was carried out under solvent-free conditions, with different molar quantities of pyrenebutyl methyl ether methacrylate (PybuMA) and PEGMA, in the presence of tricaprylmethylammonium (Aliquat 336®) persulfate as a radical initiator. The obtained PEGPy hydrogels were characterized by FT-IR spectroscopy, confirming the effective incorporation of the PybuMA monomer into the polymer backbone. The thermal properties of the hydrogels were determined using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). After immersing the hydrogels in deionized water at 25 °C and pH = 7, their swelling behavior was investigated by mass gain at different pH and temperature values. The introduction of PybuMA comonomer into the hydrogel resulted in a decreased swelling ability due to the hydrophobicity of PybuMA. The optical properties of PEGPy were determined by UV-visible absorption and fluorescence spectroscopies. Both monomer and excimer emission bands were observed at 379-397 and 486 nm, respectively, and the fluorescence spectra of the PEGPy hydrogel series were recorded in different solvents to explore the coexistence of monomer and excimer emissions.

Guest-Mediated Reversal of the Tumbling Process in Phosphorus-Dendritic Compounds Containing ß-Cyclodextrin Units: An NMR Study.

The conformational study of dendritic platforms containing multiple ß-cyclodextrin (ßCD) units in the periphery is relevant to determine the availability of ßCD cavities for the formation of inclusion complexes in aqueous biological systems. In this work, we performed a detailed conformational analysis in D2O, via 1D and 2D NMR spectroscopy of a novel class of phosphorus dendritic compounds of the type P3N3-[O-C6H4-O-(CH2)n-ßCD]6 (where n = 3 or 4). We unambiguously demonstrated that a functionalized glucopyranose unit of at least one ßCD unit undergoes a 360° tumbling process, resulting in a deep inclusion of the spacer that binds the cyclodextrin to the phosphorus core inside the cavity, consequently limiting the availability of the inner cavities. In addition, we confirmed through NMR titrations that this tumbling phenomenon can be reversed for all ßCD host units using a high-affinity guest, namely 1-adamantanecarboxylic acid (AdCOOH). Our findings have demonstrated that it is possible to create a wide variety of multi-functional dendritic platforms.

First Class of Phosphorus Dendritic Compounds Containing ß-Cyclodextrin Units in the Periphery Prepared by CuAAC.

A new class of phosphorus dendritic compounds (PDCs) having a cyclotriphosphazene (P3N3) core and decorated with six ß-cyclodextrin (ßCD) units, named P3N3-[O-C6H4-O-(CH2)n-ßCD]6, where n = 3 or 4 was designed, and the synthesis was performed using copper (I) catalyzed alkyne-azide cycloaddition (CuAAC). To obtain the complete substitution of the P3N3, two linkers consisting of an aromatic ring and an aliphatic chain of two different lengths were assessed. We found that, with both linkers, the total modification of the periphery was achieved. The two new obtained dendritic compounds presented a considerably high water solubility (>1 g/mL). The compounds comprised in this new class of PDCs are potential drug carrier candidates, since the conjugation of the ßCD units to the P3N3 core through the primary face will not only serve as surface cover but, also, provide them the faculty to encapsulate various drugs inside the ßCDs cavities.

Obtainment and Characterization of Hydrophilic Polysulfone Membranes by N-Vinylimidazole Grafting Induced by Gamma Irradiation.

Polysulfone (PSU) film and N-vinylimidazole (VIM) were used to obtain grafted membranes with high hydrophilic capacity. The grafting process was performed by gamma irradiation under two experiments: (1) different irradiation doses (100-400 kGy) and VIM 50% solution; (2) different concentration of grafted VIM (30-70%) and 300 kGy of irradiation dose. Characteristics of the grafted membranes were determined by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), contact angle, swelling degree, desalination test, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Both experiments indicated that the absorbed dose 300 kGy and the VIM concentration, at 50% v/v, were effective to obtain PSU grafted membranes with 14.3% of grafting yield. Nevertheless, experimental conditions, 400 kGy, VIM 50% and 300 kGy, VIM 60-70% promoted possible membrane degradation and VIM homopolymerization on the membrane surface, which was observed by SEM images; meanwhile, 100-200 kGy and VIM 30-50% produced minimal grafting (2 ± 0.5%). Hydrophilic surface of the grafted PSU membranes by 300 kGy and VIM 50% v/v were corroborated by the water contact angle, swelling degree and desalination test, showing a decrease from 90.7° ± 0.3 (PSU film) to 64.3° ± 0.5; an increment of swelling degree of 25 ± 1%, and a rejection-permeation capacity of 75 ± 2%. In addition, the thermal behavior of grafted PSU membranes registered an increment in the degradation of 20%, due to the presence of VIM. However, the normal temperature of the membrane operation did not affect this result; meanwhile, the glass transition temperature (Tg) of the grafted PSU membrane was found at 185.4 ± 0.5 °C, which indicated an increment of 15 ± 1%.

Efficient modification of PAMAM G1 dendrimer surface with ß-cyclodextrin units by CuAAC: impact on the water solubility and cytotoxicity.

The toxicity of the poly(amidoamine) dendrimers (PAMAM) caused by the peripheral amino groups has been a limitation for their use as drug carriers in clinical applications. In this work, we completely modified the periphery of PAMAM dendrimer generation 1 (PAMAM G1) with ß-cyclodextrin (ß-CD) units through the Cu(i)-catalyzed azide-alkyne cycloaddition (CuAAC) to obtain the PAMAM G1-ß-CD dendrimer with high yield. The PAMAM G1-ß-CD was characterized by 1H- and 13C-NMR and mass spectrometry studies. Moreover, the PAMAM G1-ß-CD dendrimer showed remarkably higher water solubility than native ß-CD. Finally, we studied the toxicity of PAMAM G1-ß-CD dendrimer in four different cell lines, human breast cancer cells (MCF-7 and MDA-MB-231), human cervical adenocarcinoma cancer cells (HeLa) and pig kidney epithelial cells (LLC-PK1). The PAMAM G1-ß-CD dendrimer did not present any cytotoxicity in cell lines tested which shows the potentiality of this new class of dendrimers.

Encapsulation of Antihypertensive Peptides from Whey Proteins and Their Releasing in Gastrointestinal Conditions.

Antihypertensive peptide fraction from whey protein hydrolysate <3 kDa (measured as angiotensin-converting enzyme (ACE) activity %) was isolated and encapsulated into three composite materials: alginate-collagen, alginate Arabic gum, and alginate-gelatin. The release behavior of peptide fraction from capsules was analyzed according to the encapsulation material efficiency, the characteristics of the capsules, and the released antihypertensive peptides during gastrointestinal digestion. The highest encapsulation efficiency was found in capsules of alginate Arabic gum (95%). In this case, the released peptides incremented their ACE activity (85%) after the digestion process, with respect to the initial ACE activity (74%). Whey antihypertensive fraction revealed five peptide sequences; however, other amino acid sequences were released from digested capsules. Protein databases confirmed some antihypertensive sequences indicating the peptides content from ß-Lg and α-La. Consequently, new peptides could be revealed from whey antihypertensive fraction.

Synthesis and Characterization of Clay Polymer Nanocomposites of P(4VP-co-AAm) and Their Application for the Removal of Atrazine.

Atrazine (ATZ) is an herbicide which is applied to the soil, and its mechanism of action involves the inhibition of photosynthesis. One of its main functions is to control the appearance of weeds in crops, primarily in corn, sorghum, sugar cane, and wheat; however, it is very toxic for numerous species, including humans. Therefore, this work deals with the adsorption of ATZ from aqueous solutions using nanocomposite materials, synthesized with two different types of organo-modified clays. Those were obtained by the free radical polymerization of 4-vinylpyridine (4VP) and acrylamide (AAm) in different stoichiometric ratios, using tetrabutylphosphonium persulfate (TBPPS) as a radical initiator and N,N'-methylenebisacrylamide (BIS) as cross-linking agent. The structural, morphological, and textural characteristics of clays, copolymers, and nanocomposites were determined through different analytical and instrumental techniques, i.e., X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Adsorption kinetics experiments of ATZ were determined with the modified and synthesized materials, and the effect of the ratio between 4VP and AAm moieties on the removal capacities of the obtained nanocomposites was evaluated. Finally, from these sets of experiments, it was demonstrated that the synthesized nanocomposites with higher molar fractions of 4VP obtained the highest removal percentages of ATZ.

Meloxicam en cirugía dentomaxilar. Ensayo clínico doble ciego prospectivo controlado con ibuprofeno / Meloxicam in oral and maxillofacial surgery. A prospective double blind controlled clinical trial with ibuprofen

Se estudiaron 120 paciente con dolor odontológico postoperatorio, mediante un diseño prospectivo, doble ciego dummy de grupos paralelos. El tratamiento consistió en comprimidos de 15 mg. de Meloxicam (60 pacientes) en toma única o de 200 mg de ibuprofeno (60 pacientes) cada 8 hs, durante 48 horas. Ambas drogas indujeron una reducción altamente significativa de la intensidad del dolor espontáneo evaluado mediante EVA en el control de las 24 horas (M: 5,45 a 1.74; I: 5,49 a 1,47). En el control final 49 de los 60 medicados con Meloxicam y 52 de los 60 tratados con ibuprofeno estuvieron libres de dolor o presentaron intensidades leves. El número de fracasos por ineficacia fue 4 en el grupo con Meloxicam y 2 en el de ibuprofeno. Durante el primer día 4 pacientes refirieron cefaleas y 1 epigastralgia en el grupo con Meloxicam, que desaparecieron espontáneamente con la prosecución del tratamiento. La evaluación global realizada por el odontólogo y el paciente al finalizar el estudio consideró a ambos tratamientos como muy buenos en un 80 por ciento, porcentaje que se incrementó a más del 95 por ciento cuando se juzgó la tolerancia

Meloxicam en cirugía dentomaxilar. Ensayo clínico doble ciego prospectivo controlado con ibuprofeno / Meloxicam in oral and maxillofacial surgery. A prospective double blind controlled clinical trial with ibuprofen

Se estudiaron 120 paciente con dolor odontológico postoperatorio, mediante un diseño prospectivo, doble ciego dummy de grupos paralelos. El tratamiento consistió en comprimidos de 15 mg. de Meloxicam (60 pacientes) en toma única o de 200 mg de ibuprofeno (60 pacientes) cada 8 hs, durante 48 horas. Ambas drogas indujeron una reducción altamente significativa de la intensidad del dolor espontáneo evaluado mediante EVA en el control de las 24 horas (M: 5,45 a 1.74; I: 5,49 a 1,47). En el control final 49 de los 60 medicados con Meloxicam y 52 de los 60 tratados con ibuprofeno estuvieron libres de dolor o presentaron intensidades leves. El número de fracasos por ineficacia fue 4 en el grupo con Meloxicam y 2 en el de ibuprofeno. Durante el primer día 4 pacientes refirieron cefaleas y 1 epigastralgia en el grupo con Meloxicam, que desaparecieron espontáneamente con la prosecución del tratamiento. La evaluación global realizada por el odontólogo y el paciente al finalizar el estudio consideró a ambos tratamientos como muy buenos en un 80 por ciento, porcentaje que se incrementó a más del 95 por ciento cuando se juzgó la tolerancia (AU)

Endocarditis infecciosa / Infectious endocarditis

El autor describe la endocarditis infecciosa, su etiología y la incidencia que las maniobras odontológicas han demostrado a la aparición de la enfermedad. Se subrayan con énfasis los aspectos relativos a la prevención de la E.I. en el tratamiento bucodental, tanto por medio de procedimientos locales, cuanto a través de una medicación antibiótica adecuada

Endocarditis infecciosa / Infectious endocarditis

El autor describe la endocarditis infecciosa, su etiología y la incidencia que las maniobras odontológicas han demostrado a la aparición de la enfermedad. Se subrayan con énfasis los aspectos relativos a la prevención de la E.I. en el tratamiento bucodental, tanto por medio de procedimientos locales, cuanto a través de una medicación antibiótica adecuada (AU)