Delamination of 2D coordination polymers: The role of solvent and ultrasound.

Two novel cadmium-based 2D coordination polymers have been synthesized and characterized. Experimental results evidence that the best delamination processes occurs when weak interactions dominate the cohesion between layers and solvent molecules are occluded within the crystalline network. In this case, the delamination of the crystals occurs spontaneously in water. On top of that, and thanks to the high stability of the resulting (flake) colloidal dispersions, we have completed a detailed study of the sonication assisted delamination impact by: I) comparison of two different sonication approaches (bath vs. tip sonication) and II) optimization of final flake morphology and yield by controlling solvent and sonication time. Our results definitely pave the way for the fabrication and implementation of 2D coordination polymers using ultrasound.

Dual T1/ T2 Nanoscale Coordination Polymers as Novel Contrast Agents for MRI: A Preclinical Study for Brain Tumor.

In the last years, extensive attention has been paid on designing and developing functional imaging contrast agents for providing accurate noninvasive evaluation of pathology in vivo. However, the issue of false-positives or ambiguous imaging and the lack of a robust strategy for simultaneous dual-mode imaging remain to be fully addressed. One effective strategy for improving it is to rationally design magnetic resonance imaging (MRI) contrast agents (CAs) with intrinsic T1/ T2 dual-mode imaging features. In this work, the development and characterization of one-pot synthesized nanostructured coordination polymers (NCPs) which exhibit dual mode T1/ T2 MRI contrast behavior is described. The resulting material comprises the combination of different paramagnetic ions (Fe3+, Gd3+, Mn2+) with selected organic ligands able to induce the polymerization process and nanostructure stabilization. Among them, the Fe-based NCPs showed the best features in terms of colloidal stability, low toxicity, and dual T1/ T2 MRI contrast performance overcoming the main drawbacks of reported CAs. The dual-mode CA capability was evaluated by different means: in vitro phantoms, ex vivo and in vivo MRI, using a preclinical model of murine glioblastoma. Interestingly, the in vivo MRI of Fe-NCPs show T1 and T2 high contrast potential, allowing simultaneous recording of positive and negative contrast images in a very short period of time while being safer for the mouse. Moreover, the biodistribution assays reveals the persistence of the nanoparticles in the tumor and subsequent gradual clearance denoting their biodegradability. After a comparative study with commercial CAs, the results suggest these nanoplatforms as promising candidates for the development of dual-mode MRI CAs with clear advantages.

Solvent-Tuned Supramolecular Assembly of Fluorescent Catechol/Pyrene Amphiphilic Molecules.

The synthesis and structuration of a novel low-molecular-weight amphiphilic catechol compound is reported. The combination of a hydrophilic tail containing a catechol unit and a pyrene-based hydrophobic head favors solvent-tuned supramolecular assembly. Formation of hollow nanocapsules/vesicles occurs in concentrated solutions of polar protic and nonprotic organic solvents, whereas a fibril-like aggregation process is favored in water, even at low concentrations. The emission properties of the pyrene moiety allow monitoring of the self-assembly process, which could be confirmed by optical and electronic microscopy. In organic solvents and at low concentrations, this compound remains in its nonassembled monomeric form. As the concentration increases, the aggregation containing preassociated pyrene moieties becomes more evident up to a critical micellar concentration, at which vesicle-like structures are formed. In contrast, nanosized twist beltlike fibers are observed in water, even at low concentrations, whereas microplate structures appear at high concentrations. The interactions between molecules in different solvents were studied by using molecular dynamics simulations, which have confirmed different solvent-driven supramolecular interactions.

Coordination polymer particles with ligand-centred pH-responses and spin transition.

A bis-catechol ligand connected through an imine bond is used to fabricate switchable coordination polymer particles with pH-tuned spin transition responses.

[Use of the urologic resectoscope in the treatment of rectal pathology. Analysis of our experience and review of the literature]. / Utilización del resector urológico en el tratamiento de patología rectal. Análisis de nuestra experiencia y revisión de la literatura.

Treatment of rectal polypoid disease, particularly villous adenoma, by electrocoagulation has proven its efficacy in a large number of cases. However, it does not permit adequate control or analysis of the specimen because the morbid excrescence is destroyed. Transsphincteric or transanal surgery, anterior resection or abdominoperineal amputation are generally too aggressive for a recurrent but benign condition. The enhanced efficacy of other therapeutic modalities such as chemo-, immuno- or radiotherapy will undoubtedly be beneficial to conservative surgical management of a malignant rectal pathology. Our initial experience in 15 patients with different rectal tumors is reported. These patients were treated by endoscopic transanal resection (ETAR) utilizing the urologic resectoscope. Local control of the disease process was achieved in 66.6% of the cases with scant morbidity and a mortality rate of 7.3% (1 case). The foregoing results and those reported in the literature indicate that ETAR is a valid alternative surgical procedure for definitive treatment of sessile, villous, or mixed adenomatous polyps and certain cases of rectal adenocarcinoma. Moreover, this procedure has proved effective as palliative treatment in advanced rectal adenocarcinoma and obviates the need for stomas.

[Symptomatic simple cyst of the kidney. Treatment using puncture-aspiration and sclerosis with 95% ethanol]. / Quistes renales simples sintomáticos. Tratamiento mediante punción-aspiración y esclerosis con etanol 95 por 100.

Puncture of cystic renal masses is useful in diagnosing a small number of cases when commonly used imaging techniques cannot determine the benign nature of the liquid mass with total accuracy. It can also be used as a therapeutic procedure in those cases with symptomatology arising from the presence of a renal cyst or functional alterations. In the present study, we report our experience using puncture-aspiration and sclerosis with 95% ethanol instillation in 12 renal cysts causing different symptoms. The procedure achieved good overall results with practically no complications. In 10 of the 12 cases the procedure was performed on an outpatient basis.

[Adrenal gland myelolipoma: apropos of a case]. / Mielolipoma suprarrenal: a propósito de un caso.

The myelolipoma is an uncommon benign tumour of the suprarrenal gland, composed of fat and hematopoietic tissue. We submit a case diagnosed preoperatively by means of echography and T.A.C. and treated surgically with tumoural excision. The gland was preserved to a large extent. We comment on etiopathogenic and diagnostic aspects.

[Incomplete bladder partition. Comments. A clinical case]. / Tabique vesical incompleto. Comentarios. A un caso clínico.

The authors present a rare case of incomplete vesical partition wall in a 59 years old woman, with mictional troubles and repeated cystitis which was surgically resolved by the abdominal way with excellent results. They finally review the different possibilities of vesical partition.