No abstract

The carbonyl stress that leads to the formation of advanced glycation end products (AGEs) has drawn much attention recently because of its micro- and macrovascular implications. During monitoring of methylglyoxal (MG), the efficiency of phenolics to directly trap MG can be demonstrated. Twenty compounds consisting of a single benzene ring structure with the addition of at least one hydroxyl group were allowed to react with MG at 37 °C for 1 h under physiological conditions in pH 7.4 phosphate buffer solution. Compounds composed of a benzene structure with a mono-hydroxyl substitute cannot react with MG. Among benzenediols and di-hydroxyl benzoic acids, only hydroquinone reacted with MG and showed a 13% decrease in MG. Nevertheless, high reactivity was shown for 3 benzenetriols. The percentages of MG remaining were 45%, 51%, and 36% for pyrogallol, 1,2,4-trihydroxybenzene, and 1,3,5-trihydroxybenzene, respectively. When a carboxyl group is added to the benzenetriols, steric hindrance and carbon electron charges on benzene ring are the influential factors in reactivity. Using computational chemistry calculations, a carbon electron charge of -0.24 was the minimum value for high reactivity.

No abstract

MRI for in vivo stem cell tracking remains controversial. Here we tested the hypothesis that MRI can track the long-term fate of the superparamagnetic iron oxide (SPIO) nanoparticles labelled mesenchymal stem cells (MSCs) following intramyocardially injection in AMI rats. MSCs (1 × 106) from male rats doubly labeled with SPIO and DAPI were injected 2 weeks after myocardial infarction. The control group received cell-free media injection. In vivo serial MRI was performed at 24 hours before cell delivery (baseline), 3 days, 1, 2, and 4 weeks after cell delivery, respectively. Serial follow-up MRI demonstrated large persistent intramyocardial signal-voids representing SPIO during the follow-up of 4 weeks, and MSCs did not moderate the left ventricular dysfunction. The TUNEL analysis confirmed that MSCs engrafted underwent apoptosis. The histopathological studies revealed that the site of cell injection was infiltrated by inflammatory cells progressively and the iron-positive cells were macrophages identified by CD68 staining, but very few or no DAPI-positive stem cells at 4 weeks after cells transplantation. The presence of engrafted cells was confirmed by real-time PCR, which showed that the amount of Y-chromosome-specific SRY gene was consistent with the results. MRI may not reliably track the long-term fate of SPIO-labeled MSCs engraftment in heart.

SummaryHorse oil contains linoleic, palmitoleic and unsaturated fatty acids that are similar to those in human skin, and may therefore be an ideal substance from which to isolate biosurfactants for cosmetic products to improve human skin quality. Herein, an innovative approach was developed to synthesise sophorolipids from horse oil by hydrolysis, followed by fermentation using the yeast Candida bombicola. The yield of sophorolipids from direct fermentation of horse oil and hydrolysed horse oil was 40.6 ± 1.3 g l−1 and 58.4 ± 1.8 g l−1 respectively. To further increase the yield, 30–40 g l−1 glucose was added in a fed‐batch fermentation process to maintain the pH between 4.0 and 4.5, resulting in a conversion yield of 71.7 ± 0.8 g l−1. The purity and structure of the synthesised sophorolipids were analysed by ultra‐performance liquid chromatography‐mass spectrometry and nuclear magnetic resonance. An in vitro human dermal fibroblast model was used as a surrogate for human skin to measure elastase inhibition activity. Antiwrinkle properties of isolated sophorolipids were better than those of horse oil or hydrolysed horse oil in several in vitro assays. Furthermore, no cytotoxicity was observed at a concentration of 50 μg ml−1, and wound‐healing capacity was evident in a cell culture model. Additionally, the synthesised sophorolipids attenuated lipopolysaccharide‐induced expression of inflammatory cytokines in macrophages, and efficiently inhibited several strains of bacteria and yeast. In conclusion, fed‐batch fermentation of hydrolysed horse oil is a novel and efficient approach for producing high‐quality and high‐yield sophorolipids that exhibit great potential as cosmetic ingredients.