Lymphatic targeting with nanoparticulate system.

Much effort has been made to achieve lymphatic targeting of drugs using colloidal carriers. This paper reviews the recent progress in the development of biodegradable nanoparticulate systems, including nanospheres, emulsions, and liposomes. The major purpose of lymphatic targeting is to provide an effective anticancer chemotherapy to prevent the metastasis of tumor cells by accumulating the drug in the regional lymph node via subcutaneous administration. The objectives of lymph targeting also involve the localization of diagnostic agents to the regional lymph node to visualize the lymphatic vessels before surgery, and the improvement of peroral bioavailability of macromolecular drugs, like polypeptides or proteins, which are known to be selectively taken up from the Peyer's patch in the intestine. Nanocapsules, which are ultrafine oily droplet-coated polymeric substances, are probably one of the most promising candidates of colloidal carriers. Surface engineering by the interfacial deposition method can provide a suitable size distribution and necessary surface characteristics to the nanocapsules. Our recent in vivo study proved that polyisobutylcyanoacrylate nanocapsules showed enhanced accumulation of drug in the lymph node, compared with other carriers such as emulsions and liposomes.