This study was conducted to evaluate the accumulation and distribution of hydrophobically modified glycol chitosan (HGC) as a degradable nanoparticle in the body. To determine the movement of degradable HGC nanoparticles in the body, 20 mg/kg of lutetium177-labeled HGC (Lu177-HGC) with the size ranging from 320 to 400 nm was injected intravenously into ICR mice, and the amount of radioactivity remaining in blood and several organs was measured at various time points during the period of 5 days. In the pharmacokinetics analysis using the Lu177 radioisotope, the free Lu177 was mainly distributed and accumulated in the order of kidney>liver>lung at 1 day after the injection of the radioisotope. However, the Lu177-HGC showed a high distribution of nanoparticles in the order of liver>spleen>kidney during the experimental period of 5 days. These results would provide a basic pharmacokinetics for the use of HGC as a drug carrier in drug delivery system.

The ultimate goal of this study is to assess the accumulation and distribution of hydrophobically modified glycol chitosan (HGC) as a degradable nanoparticle in the body. To understand the movement of degradable nanoparticle HGC in the body, we intravenously injected a dose of 20 mg/kg of Cy5.5-labeled HGC with size ranging from 320 to 400 nm into ICR mice, and measured the amount of fluorescence remaining in blood and several organs at various time intervals. In blood, the level of Cy5.5-labeled HGC was the highest at 15 min, then after 30 min it decreased rapidly and reached a plateau form 30 min to 28 days. In the tissue we confirmed the presence of nanoparticles at high levels in the order of kidney>liver>submandibular gland until 28 days after injection. However, we did not find the presence of the particles in the brain or testes. These results will provide basic information on HGC as a drug delivery agent.