Obesity is closely related with insulin resistance and chronic inflammation. Here, we report that unsaturated lipid-modified polyoxovanadates (ULPOVs) can restrict weight gain of diet-induced obese mice and improve their glycemic control and obesity-associated inflammation. Oral administration of the sub-nanosized ULPOVs at a low dosage for 7 weeks reduces the body weight and almost normalizes the blood glucose levels of obese mice fed on a high-fat diet. ULPOV treatment increases the activity of the nuclear receptor peroxisome proliferator-activated receptor γ (PPARγ) and reduces intestinal caloric intake, which may be the main reason for blood sugar and body weight control. In addition to insulin-sensitizing, PPARγ activation induced by ULPOV treatment in obese mice with atopic dermatitis (AD) promotes the type 2 T helper (T_H2) cell selective responses and therapeutic effects on immune dysregulation caused by obesity. These data suggest sub-nanosized polyoxovanadate clusters as a class of potential candidates to relieve symptoms accompanied by diet-induced obesity.

Long-lasting protective immune responses are expected following vaccination. However, most vaccines alone are inability to evoke an efficient protection. The combinatory administration of adjuvants with vaccines is critical for generating the enhanced immune responses. Herein, with biocompatible poly(4-vinylpyridine) (P4VP) as template, 2.5 nm iron/molybdenum oxide cluster, {Mo₇₂Fe₃₀}, is applied as an adjuvant to co-assemble with antigens of Mycobacterium bovis via hydrogen bonding at molecular scale. Molecular scale integration of the antigens and {Mo₇₂Fe₃₀} and their full exposure to body fluid media contribute to the augmentation of both humoral and cellular immune responses of the vaccines after inoculation in mice. Anti-inflammatory factor IL-10 gradually increases after 2 weeks followed by a final back to normal level by the 5th week. The balance between proinflammatory cytokines and anti-inflammatory factors suggests that immune system can be activated in the early stage of infection by the antigens carried by the supra-particles and secrete acute inflammatory factors for host defense and anti-inflammatory factors for immune protection.