Structural and mechanistic insights into starch microgel/anthocyanin complex assembly and controlled release performance.

We report a self-assembly method for the fabrication of multilayer-starch-based microgels used for anthocyanin encapsulation. Alcohol-heating treatment and ionization reactions were employed to reduce the crystallinity of starch and introduce ionic groups on the molecule to further cross-link it with sodium trimetaphosphate and produce a starch microgel. The molecular interactions between the starch and the anthocyanins facilitated the anthocyanin encapsulation and the starch-microgel/anthocyanin complexes with one, two, and three self-assembled layers were obtained. The Lay-1 microgel exhibited an encapsulation efficiency of 50.1% when the anthocyanin concentration, cross-linking starch concentration, contact time, and temperature were 0.25 mg/mL, 1.5 mg/mL, 3 h, and 40 °C, respectively. An increase in the number of layers resulted in a more compact microgel structure with the zeta potential presenting variations upon structural changes. Furthermore, the encapsulated anthocyanins presented a slow release from Lay-1, while the multilayered microgels (Lay-2 and Lay-3) displayed outstanding encapsulation stability. This study gives an insight on the encapsulation and release of anthocyanins by starch microgels, and provides a novel strategy for the design of starch-based encapsulation materials presenting great stability.

[Influence of Jiangu decoction on peroxisome proliferator-activated receptor (PPAR) in the femoral head of rabbits with steroid-induced femoral head necrosis].

OBJECTIVE: The Jiangu decoction is used in the treatment of steroid-induced femoral head necrosis in clinical experiences, which has functions of tonifying kidney and activating blood, and invigorating spleen to remove phlegm. The decoction is mainly composed of Radix Polygoni Multiflori, Rhizoma alismatis Rhizoma Drynariae, haw, medlar, Radix Astragali, radix rehmanniae, angelica, Radix Codonopsis, radix salviae miltiorrhizae, Fructus Ligustri Lucidi, licorice, pharmaceutical composition. This study was designed to investigate the influence of Jiangu decoction on peroxisome proliferator-activated receptor gamma (PPARgamma) in the femoral head of rabbits with steroid-induced femoral head necrosis. METHODS: Eighteen adult SPF healthy New Zealand rabbits were divided into 3 groups: control group, model group, Jiangu decoction group. The rabbits of Jiangu decoction group orally received Jiangu decoction suspension with a dose of 10 ml/kg each day and the drug content was 0.719 g/ml. The rabbits in control and model groups were given saline with a dose of 10 ml/kg. The methylprednisolone sodium succinate was injected intramuscularly into left leg with a dose of 40 mg/kg. Then the rabbits were fed continuously for 3 weeks. The glucocorticoid levels, PPARgamma and plasma glucocorticoid levels in the femoral head were measured before and after modeling. RESULTS: Before model established, the plasma glucocorticoid levels had no significant difference among three groups (P=0.301). At 3 weeks after model established,the plasma glucocorticoid level of rabbits in model group increased compared to the control group (P=0.001); and the plasma glucocorticoid level of rabbits in Jiangu decoction group decreased compared with model group (P=0.001). The glucocorticoid level in the local femoral head of rabbits in model group increased compared to the control group (P=0.001); and the glucocorticoid level in the local femoral head of rabbits in Jiangu decoction group decreased compared with model group (P=0.001). The PPARgamma level in the local femoral head of rabbits in model group increased compared to the control group (P=0.018);and the PPARgamma level in the local femoral head of rabbits in Jiangu decoction group decreased compared with model group (P=0.033). CONCLUSION: The Jiangu decoction is effective to inhibit the femoral head adipogenic differentiation by decrease the PPAR content, so as to prevent and treat steroid-induced femoral head necrosis.