Mechanochemical Activation of a Metal–Organic Framework Embedded within a Thermoplastic Polyurethane Matrix: Probing Fluorogenic Stress-Sensing

Here, a mechanochemically triggered Cu(I) bis(N-heterocyclic carbene [NHC))-based metal–organic framwork (MOF) embedded into a thermoplastic polyurethane (TPU)-matrix is reported. The induced fluorogenic copper-catalyzed azide–alkyne cycloaddition (CuAAC) reveals the stressed parts within the thermoplastic PU via a simple optical detection. As determined via oscillating tensile rheology on dumbbell-shaped samples of TPU, a MOF, containing 4.66% copper, catalyzes the fluorogenic CuAAC between the nonfluorescent precursor dyes, 8-azidonaphthalen-2-ol, and 3-hydroxyphenylacetylene. After mechanical activation of the MOF situated inside the TPU, the fluorescent 8-(4-(3-hydroxyphenyl)-1,2,3-triazol-1-yl)naphthalen-2-ol dye is formed. Monitoring the formation of the dye inside the TPU via fluorescence spectrometry at λ_ex = 458 nm shows an increase of the fluorescence intensity up to 60–70%. It is demonstrated that a dumbbell-shaped TPU, subjected to higher stress, displays higher fluorescence than the surrounding other areas, thus effectively functioning as a three-in-one stress-sensor system.     

Lutein ameliorates high-fat diet-induced obesity,fatty liver,and glucose intolerance in C57BL/6J mice

Obesity is a multi-factorial metabolic syndrome that increases the risk of cardiovascular diseases, diabetes, and cancer. We recently demonstrated the antiadipogenic efficacy of lutein using a 3 T3-L1 cell culture model. This study aimed to examine the antiobesity efficacy of lutein on high-fat (60% kcal fat) diet-induced C57BL/6J obese mice model. Lutein (300 and 500 μM), Orlistat (30 mg/kg body weight - positive control), and its combination (orlistat, 15 mg/kg body weight+lutein, 300 μM) were administered in high-fat diet (HFD)-fed mice every other day for 24 weeks. The effect on serum and hepatic lipid parameters was estimated using biochemical assay kits. The adipose tissue expression of adipocyte differentiation markers at gene and protein levels was analyzed by RT-PCR and western blotting, respectively. The results showed that lutein administration and drug significantly reduced epididymal and abdominal adipose tissue weights. Further, lutein reduced the serum cholesterol and LDL-C concentration compared to the HFD group. The HFD-induced elevation in the hepatic triglycerides and cholesterol levels were significantly blocked by lutein and its combination with the drug. Similarly, lutein and its drug combination efficiently lowered the HFD-mediated elevated blood glucose levels. Lutein downregulated the expression of CEBP-α, PPAR-γ, and FAS in the epididymal adipose tissue. Thus, supplementation of lutein may control diet-induced obesity and associated complications in the human population.