The aim of the present study was to investigate the effects of Bifidobacterium adolescentis (Bif) supplementation on visceral fat accumulation and insulin sensitivity of the metabolic syndrome in HF-diet-fed rats. Adult male Wistar rats (n 10 per group) were fed four different experimental diets for 12 weeks as follows: standard diet; high-fat (HF) diet; a mix of HF diet and Bif; a mix of standard diet and Bif. Liver, mesenteric fat, epididymal fat, retroperitoneal fat, and inguinal fat, pancreas and triceps surae in all four groups of the rats were weighed, while liver steatosis and insulin sensitivity were evaluated at the end point of the study. As the number of intestinal Bifidobacterium species decreased obviously, fat pad weight and body weight increased significantly in the HF group compared with in the other three groups (P , 0·05). Addition of Bif led to a reduction in body weight and fat pad weight (P , 0·05). With an increase in liver weight, more severe steatosis of hepatocytes was observed in the HF group compared with in the other three groups. A significant decrease of the glucose infusion rate and pancreas weight was found in the HF group (P , 0·05). This deleterious effect was alleviated when Bif was added to the diets. Bifidobacterium supplementation ameliorated visceral fat accumulation and insulin sensitivity of the metabolic syndrome in HF-diet-fed rats.Key words: Bifidobacterium: Metabolic syndrome: Insulin sensitivity: Visceral fat: RatsThe metabolic syndrome is a significant clinical problem characterised by insulin resistance, hyperinsulinaemia, dyslipidaemia, hypertension and impaired glucose tolerance (1,2) . According to recent estimates, approximately 215 million people worldwide suffer from diabetes and 80 -90 % of them from type 2 diabetes (3) . The modern lifestyle of increased intake of a high-energy-dense diet associated with decreased energy expenditure also contributes to the current rising prevalence of obesity and type 2 diabetes (4) . Recent epidemiological studies also revealed that 90 % of all patients with type 2 diabetes are or have been overweight, and indicated that obesity is a strong risk factor and cause of type 2 diabetes and associated metabolic disturbances (5,6) . The events of hyperglycaemia and hyperlipidaemia, and their association present major risk factors for the development of diabetic and cardiovascular complications (7) . To reduce these serious complications and negative outcome of the metabolic syndrome, the control not only of blood glucose but also of lipids is necessary (8) . Therefore, new medicinal agents with dual properties related to controlling both blood glucose and lipids are in great demand. The currently available therapeutic options such as dietary modification or a combination of synthetic antidiabetic, hypolipidaemic drugs have their own limitations and undesirable side-effects (7) . Hence, there is an increased demand to search and evaluate traditional approaches for the treatment of metabolic disorders.An innovative hypothes...

Articular cartilage defect has limited self-repair ability due to the lack of blood supply and innervation, which may lead to knee osteoarthritis afterwards. Injectable hydrogels are demonstrated possessing outstanding properties as biomimetic scaffolds in cartilage tissue engineering, while the effect of biophysical properties on the efficacy of cartilage regeneration has not been revealed. Herein, the poly(ethylene glycol)-polypeptide triblock copolymers with different ratios of alanine to phenylalanine were synthesized. The sol-to-gel transition temperature and the critical gelation concentration decreased as the increased amount of phenylalanine unit, resulting in the enlarged pore size and enhanced mechanical strength. These features lead to better regeneration of hyaline-like cartilage with reduced fibrous tissue formation, indicating great potential of thermosensitive polypeptide hydrogels for efficient cartilage repair.

A series of poly(amino acid)-containing copolymers with gradient pH-sensitive side groups were synthesized through ring-opening reaction of succinic anhydride (SA), cis-cyclohexene-1,2-dicarboxylic anhydride (CDA), cis-aconitic anhydride (CA), and dimethylmaleic anhydride (DMMA) initiated by the amino groups in methoxy poly(ethylene glycol)-block-poly(L-lysine). Subsequently, four pH-responsive polyion complex (PIC) micelles (denoted as SAD, CDAD, CAD and DMMAD) were prepared through the electrostatic interaction between pH-responsive negatively charged copolymers and positively charged doxorubicin for adjustable intracellular drug delivery. Due to the differences among the acid-sensitive side amide bonds, these micelles were proved to have gradient pH-sensitivity in the following order: SAD < CDAD < CAD < DMMAD. The in vitro drug release rate was consistent with the sensitivity order of the micelles. The intracellular DOX release behaviors and cytotoxicities of the PIC micelles could also be adjusted by the sensitivities of copolymers. All these different characters among the PIC micelles would be further applied for "on demand" intracellular targeting chemotherapy in clinics.