Abstract
BACKGROUND: Mesenteric lymph nodes (MLNs) are critical draining lymph nodes of the immune system that accommodate more than half of the body's lymphocytes, suggesting their potential value as a cancer immunotherapy target. Therefore, efficient delivery of immunomodulators to the MLNs holds great potential for activating immune responses and enhancing the efficacy of antitumor immunotherapy. Self-microemulsifying drug delivery systems (SMEDDS) have attracted increasing attention to improving oral bioavailability by taking advantage of the intestinal lymphatic transport pathway. Relatively little focus has been given to the lymphatic transport advantage of SMEDDS for efficient immunomodulators delivery to the MLNs. In the present study, we aimed to change the intestinal lymphatic transport paradigm from increasing bioavailability to delivering high concentrations of immunomodulators to the MLNs. METHODS: Chlorogenic acid (CHA)-encapsulated SMEDDS (CHA-SME) were developed for targeted delivery of CHA to the MLNs. The intestinal lymphatic transport, immunoregulatory effects on immune cells, and overall antitumor immune efficacy of CHA-SME were investigated through in vitro and in vivo experiments. RESULTS: CHA-SME enhanced drug permeation through intestinal epithelial cells and promoted drug accumulation within the MLNs via the lymphatic transport pathway. Furthermore, CHA-SME inhibited tumor growth in subcutaneous and orthotopic glioma models by promoting dendritic cell maturation, priming the naive T cells into effector T cells, and inhibiting the immunosuppressive component. Notably, CHA-SME induced a long-term immune memory effect for immunotherapy. CONCLUSIONS: These findings indicate that CHA-SME have great potential to enhance the immunotherapeutic efficacy of CHA by activating antitumor immune responses.