Nanoparticles for Lymph Node-Directed Delivery.

Lymph nodes are organs that control immune cells and provide a major pathway for primary tumors to metastasize. A nanoparticles-based strategy has several advantages that make it suitable for achieving effective lymphatic delivery. First, the size of nanoparticles can be tailored to meet a size range appropriate for lymphatic migration. In addition, functionalized nanoparticles can target cells of interest for delivery of drugs or imaging probes. Existing lymph node contrast agents map all lymph nodes regardless of metastasis status; however, by using nanoparticles, it is possible to selectively target lymphatic metastases. Moreover, using functionalized nanoparticles, it is possible to specifically deliver anticancer drugs to metastatic lymph nodes. In this review, we introduce the use of nanoparticles for lymphatic mapping, in particular highlighting design considerations for detecting metastatic lymph nodes. Furthermore, we assess trends in lymph node-targeting nanoparticles in clinical practice and suggest future directions for lymph node-targeting nanoparticles.