The active form of vitamin D3, 1,25-dihydroxyvitamin D₃ (aVD₃), is known to exert beneficial effects in the treatment of autoimmune diseases because of its immunosuppressive effects. However, clinical application of aVD₃ remains limited because of the potential side effects, particularly hypercalcemia. Encapsulation of aVD₃ within biodegradable nanoparticles (NPs) would enhance the delivery of aVD₃ to antigen presenting cells, while preventing the potential systemic side effects of aVD₃. In the present study, polymeric NPs containing ovalbumin (OVA) and aVD₃ (NP[OVA+aVD₃]) were prepared via the water-in-oil-in-water double emulsion solvent evaporation method, after which their immunomodulatory effects were examined. Bone marrow-derived immature dendritic cells (DCs) treated with NP(OVA+aVD₃) did not mature into immunogenic DCs but were converted into tolerogenic DCs, which express low levels of co-stimulatory molecules and MHC class II molecules, produce lower levels of pro-inflammatory cytokines while increasing the production of IL-10 and TGF-β, and induce the generation of Tregs. Intravenous injection with NP(OVA+aVD₃) markedly suppressed the generation of OVA-specific CTLs in mice. Furthermore, OVA-specific immune tolerance was induced in mice orally administered with NP(OVA+aVD₃). These results show that biodegradable NPs encapsulating both antigen and aVD₃ can effectively induce antigen-specific immune suppression.
Animals ; Antigen-Presenting Cells ; Autoimmune Diseases ; Cholecalciferol ; Cytokines ; Dendritic Cells ; Hypercalcemia ; Immune Tolerance ; Injections, Intravenous ; Interleukin-10 ; Methods ; Mice ; Nanoparticles ; Ovalbumin ; Polymers ; T-Lymphocytes, Regulatory ; Vitamins

Objectives: This study was intended to analyze the characteristics of infrequent and frequent outpatients visiting Korean medical facilities, and find the related variables of frequent users. Methods: The data source was the Report on the Usage and Consumption of Korean Medicine (2011) published by the Ministry of Health and Welfare and Korea Institute for Health and Social Affairs. We analyzed outpatient data using SAS 9.2. Results: As much as 46.6% of the patients used Korean medical services over 11 times in 3 months. The proportion of frequent users increased depending on age, and their proportion was high in the low-income and low-education group. People with musculoskeletal disease, stroke, hypertension, and obesity were more likely to use Korean medical services. In general, patients were satisfied with their treatment, with frequent outpatients being more satisfied than infrequent outpatients. In logistic regression analysis, age and musculoskeletal disease were significant determinants of frequency of use of Korean medical services. Conclusion Age, musculoskeletal disease, and specific diseases were highly associated with frequent Korean medical utilization.