Lactosaminated N-Succinyl-chitosan: Preparation and Biodistribution into the Intestine, Bone, Lymph Nodes and Male Genital Organs after I.v. Administration

Reductive amination of N-succinyl-chitosan (1) and lactose using sodium cyanoborohydride in 1/15 M phosphate buffer (pH 6.0) for 6 d was suitable for the preparation of lactosaminated N-succinyl-chitosan (2). At 8, 24 and 48 h after i.v. administration of fluorescently labeled 1 (1') or 2 (2'), Peyer's patch, mesenteric lymph nodes, testes, prostate, preputial grand, intestine (small intestine plus cecum), femoral muscle, backbone and peritoneum were taken. Peyer's patch and mesenteric lymph nodes were put together as lymph nodes. Over 10% of dose/g tissue was distributed to the prostate and lymph nodes at 48 h post-administration in both l' and 2'.2' was easily distributed into not only the liver but also prostate, intestine, preputial gland and lymph nodes. Although galactose receptors are known to exist not only on the liver parenchymal cells but also on prostate and testes, the selective distribution of 2' into the prostate and the testes were not observed clearly. This study suggested that 1 and 2 should have possibilities for both the prevention and cure of lymph node metastasis as drug carriers.