Aptamer-functionalized AuNCs nanogel for targeted delivery of docosahexaenoic acid to induce browning of white adipocytes.

Obesity, as a global public health concern, causes a series of metabolic disorders and other diseases. Browning of white fat (white adipocytes transforming to beige adipocytes) offers an attractive approach for obesity treatment. In the present study, aptamer-functionalized nanogel of gold nanoclusters (AuNCs), termed Apt-NG, was developed as the targeted delivery vehicle of browning agent docosahexaenoic acid (DHA). Apt-NG has multiple advantages, including nanoscale size, strong autofluorescence, low toxicity, and excellent targeting capability to white adipocytes. After treatment with DHA@Apt-NG, the morphology of lipid droplets changed evidently; meanwhile the triglyceride level decreased while the mitochondrial activity increased. The DHA@Apt-NG treatment effectively up-regulated the mRNA expression levels of Ucp1, Pgc-1α, Pparg, and Prdm16, which play important roles in browning of white adipocytes. This study provides a feasible strategy to achieve efficient browning of white adipocytes based on targeted delivery nanosystems, inspiring a new idea for obesity treatment.

Comparison of Three Different Extraction Methods on Osmanthus Volatile Oil: Aroma and Biological Activity.

The osmanthus volatile oil was welcomed by consumers even if the high price since the unique and pleasant odor. Meanwhile, the low yield of osmanthus volatile oil restricts industrial production. In this work, an osmanthus volatile oil was obtained by means of a novel ultrasonic-assisted flash extraction method and was compared with the oil from hydrodistillation and supercritical fluid extraction on yield, aroma, and biological activities. The volatile oil obtained from the ultrasonic-assisted flash extraction was obtained with the petroleum ether and got a high yield at 3.51 % within a 40-min process, an increase of nearly 81 % from the single solvent extraction. This oil also showed a high aroma intensity and aroma compound concentration. Meanwhile, the oil also has the highest antioxidant ability but lower antibacterial activity against oil from hydrodistillation. It was considered that this work was helpful for the optimization of the extraction method of osmanthus volatile oil.

Browning of white adipocytes by gold nanocluster mediated electromagnetic induction heating hyperthermia.

Browning of white adipose tissue (WAT) is becoming an attractive therapeutic target for obesity. Great efforts have been made to develop effective approaches to induce browning. Unfortunately, the current methods suffer from a series of disadvantages, such as low efficiency, unsatisfactory stability, and side effects. Herein, we report a new approach to induce browning of 3T3-L1 white adipocytes based on electromagnetic induction heating (EIH) hyperthermia. In particular, adipocyte-targeting aptamer modified gold nanoclusters (Apt-AuNCs) were employed as the mediators of EIH. Apt-AuNCs had good biocompatibility and excellent targeting performance with white adipocytes. After Apt-AuNCs/EIH treatment, adipocytes with characteristic multilocular and small lipid droplets increased, and the content of triglycerides reduced effectively. Apt-AuNCs/EIH treatment also significantly increased the mitochondrial activity in adipocytes. Meanwhile, the mRNA levels of key genes that are involved in browning, for example UCP1, PRDM16, PPARγ, and PGC-1α, were upregulated. Finally, the induction mechanism of Apt-AuNCs/EIH on browning of white adipocytes was explained by the synergistic effects of EIH hyperthermia and pharmacological action of AuNCs. To the best of our knowledge, this is the first attempt on induction of browning by metal nanocluster-mediated EIH hyperthermia, thus providing an interesting and efficient channel for obesity treatment.