Figure 5

Effect of chloroquine on the biodistribution of liposomes. (a) Immunofluorescence staining of macrophages in the liver. Athymic nude mice were treated with clodronate liposomes (clodrolip; 50 mg/kg clodronate i.v.) or chloroquine (60 mg/kg/day i.p. for 7 days). DAPI, blue; macrophages (F4/80), green. Scale bar, 50 μm. (b) Accumulation of intravenously injected fluorescent liposomes in the plasma, liver, and spleen. The blood was collected and the liver and spleen were harvested 15 min, 3 h, 6 h, or 24 h post-injection of liposomes. (c,d,e) Effect of Kupffer cell depletion (clodrolip; 50 mg/kg clodronate) and chloroquine pretreatment (60 mg/kg/day for 7 days) on the biodistribution of fluorescent liposomes. The blood was collected and the organs were harvested 6 h post-injection of liposomes. (c) Detected signal in the plasma, liver, and spleen. (d) Plasma/liver and plasma/spleen accumulation ratio of liposomes (g tissue). (e) Accumulation of fluorescent liposomes in MDA-MB-231 orthotopic breast cancer tumors. Data is presented as mean ± s.d. (n = 5). Statistics by Student’s t-test. *P < 0.05; **P < 0.01; ***P < 0.001.