LAUSR

Here, antigen and adjuvant encapsulated dendritic cell‐targeted nanoparticles for immune activation in the small intestinal lymphatic system to inhibit melanoma development are described. This strategy is demonstrated using chondroitin sulfate‐coated nanoparticles (OPGMN) grafted with glycocholic acid and mannose for cationic liposomes encapsulated with ovalbumin as an antigen and polyinosine‐polycytidylic acid as a cancer‐specific adjuvant. OPGMN is absorbed in the gastrointestinal tract and delivered to the lymph nodes when orally administered. Oral delivery of OPGMN induces increased dendritic cell maturation compared to the intradermal route in the lymph node and induces T helper type 1 and type 2 responses, such as immunoglobulin G1 and G2c, interferon‐gamma, and interleukin‐2, in the blood. Repeated oral administration of OPGMN increases the population of CD3+CD8+ T cells, CD44highCD62Llow memory T cells, and CD11b+CD27+ natural killer cells in the blood. OPGMN completely prevents melanoma development in the B16F10‐bearing C57BL/6 mouse model by reducing the population of CD4+CD25+Foxp3+ regulatory T cells in the blood. This strategy is expected to prevent the recurrence of tumors after various cancer treatments.