Red fluorescent benzothiadiazole derivative loaded in different nanoformulations: Optical properties and their use in bio-imaging.

Fluorophores with optimized nonlinear optical properties have become prominent as contrast labels in laser scanning microscopy (LSM). The purpose of this work is to report on a novel benzothiadiazole derivative, namely 4,7-bis(5-((9,9-dioctyl-9H-fluoren-2-yl)ethynyl)thiophen-2-yl)benzo[c][1,2,5]thiadiazole (EFBT) and its optical performance when it is loaded into organic nanostructures intended as labels for LSM. Four different nanostructured labels were prepared: i) EFBT-loaded silica nanoparticles (SiNPs); ii) folate-bioconjugated SiNPs (SiNPs-FA); iii) EFBT-loaded PEGylated nanoparticles (NPs-PEG); and iv) EFBT-loaded folate-terminated PEGylated nanoparticles (NPs-PEG-FA). All these nanostructures are reported through a comparative study of their linear and nonlinear optical properties, including their performance as exogenous label agents in the cervical cancer cell line HeLa. This assessment of the performance of a specific fluorophore loaded into different nanostructured matrices (labels), and fairly compared under the same characterization conditions, including the LSM settings, is less common while previous reports had focused in comparing silica and PEGylated nanoparticles but loaded with different fluorophores. The results show that the internal molecular organization into each type of organic nanostructure impacted differently the properties of EFBT, where the silica matrix tend to preserve the optical performance of the fluorophore by preventing intermolecular interactions; in contrast, PEGylated nanoparticles favored molecular interactions and introduced non-radiative decay channels that degrades drastically the optical performance. Nevertheless, the use of functionalized ends entities produced a better cellular label uptake with PEGylated that with silica nanoparticles. In overall, the NPs-PEG-FA label produced the best HeLa imaging.

Low bone mineral density and associated factors in patients with haemophilia in Colombia.

INTRODUCTION: Patients with haemophilia may have lower levels of bone mineral density (BMD) compared with the general population. Moreover, haemophilic patients have increased risk factors for low bone mineral density (LBMD) such as arthropathy and resulting immobility, increasing their risk for osteoporosis and fractures. AIM: To assess the prevalence of LBMD and associated risk factors among a group of Colombian haemophilic patients. METHODS: In this case-control study, 90 patients with haemophilia A and B, over the age of five, were recruited. Controls were healthy participants matched by age, gender, body mass index (BMI), socioeconomic status, and race. All participants underwent dual energy X-ray absorptiometry (DXA) and the Global Physical Activity Questionnaire. Blood tests were collected to evaluate LBMD determinants in cases. RESULTS: BMD was lower in cases than in the control group. BMD of femoral necks was 0.907 g/cm2 in cases vs. 1.020 g/cm2 in controls (P = .019), and BMD of hips 0.930 g/cm2 in cases vs. 1030 g/cm2 in controls (P = .019). The greater the severity of haemophilia, the lower BMD in spine, femoral neck, and hips. Elevated C-protein levels were found in 44.1% of patients with LBMD and 14.8% with normal BMD (P = .003). The study found an adjusted prevalence ratio of 2.11, indicating that haemophilic patients are two times more likely to have LBMD (CI95% = 1.43-3.11 P < .001). CONCLUSION: Results from the present study showed that haemophilia was associated with a higher frequency of LBMD. Severity of haemophilia, haemophilic arthropathy, and elevated C-reactive protein levels was directly associated with LBMD.

Preparation of seven- and eight-membered boron heterocycles from different salen ligands and arylboronic acids.

Arylboronic acids and different salen ligands have been brought to reaction in a 2:1 stoichiometry in ethanol, toluene, and acetonitrile. In all cases bimetallic boronates with chiral boron atoms could be isolated with the difference that in ethanol mostly open bimetallic boronic esters are obtained, while in toluene or acetonitrile closed bimetallic complexes with a central seven- or eight-membered heterocyclic ring are formed. Both structural types have been characterized by spectroscopic techniques and X-ray crystallography showing that the reactions are diastereoselective in the case of the bimetallic heterocyclic structures. The configurations and conformations of the seven- and eight-membered rings are different, and this may depend on steric effects and/or repulsive intramolecular pi-pi interactions between the two salicylidene moieties attached to the central ring.