Intraarterial Therapy Using Micellar Nanoparticles Incorporating SN-38 in a Rabbit Liver Tumor Model

To evaluate the pharmacokinetics of intraarterial (IA) administration of micellar nanoparticles incorporating SN-38 injection compared with intravenous (IV) administration in a rabbit liver tumor model.

In this animal care committee-approved study, 18 rabbits (mean weight, 3.89 kg; range, 3.20-4.70 kg) with VX2 liver tumors were divided into two groups (IA and IV). Micellar nanoparticles incorporating SN-38 (30 mg/kg) were injected through the left hepatic artery in the IA group and the right femoral vein in the IV group. NK012 and free SN-38 in the plasma, liver parenchyma, and tumors were measured within 24 hours. Histologic examinations were conducted at 2 and 24 hours.

There were no significant differences in the serum area under the concentration-time curve (0-24 h) for free SN-38, at 1,500 and 1,310 μg∙min/mL in the IA and IV groups, respectively (P = .152). The IA group showed significantly higher free SN-38 concentrations in tumor tissues at all time points compared with the IV group (P = .002 at 3 min, P = .011 at 2 h, and P = .047 at 24 h). Histologic findings showed that significantly higher tumor necrosis ratios were observed in the IA group compared with the IV group at 24 hours (P = .028).

Micellar nanoparticles could be a promising IA drug delivery system to achieve high tumor tissue concentrations of SN-38.