Delivery of contrast agents for positron emission tomography imaging by liposomes.

摘要: Liposomes encapuslating positron emitters are applicable for diagnostic imaging and useful to investigate the real-time liposomal trafficking in vivo. Long-circulating liposomes encapsulaing [2-(18)F]-2-fluoro-2-deoxyglucose were administrated tumor-bearing mice, a PET scan was performed. Small-sized long-circulating (100 nm) tended accumulate tumor tissues of mice as compared with conventional liposomes. Then size effect on investigated. Large-sized (>300 accumulated liver spleen time dependent manner. On contrary, small-sized ones (<200 transiently right after injection, but accumulation decreased dependently, suggesting that, although majority small remain bloodstream, some extravasate once into interstitial spaces which re-enter bloodstream again. Next so-called liposomes, i.e., modified ganglioside GM1, palmityl glucuronide (PGlcUA), polyethylene glycol (PEG), examined. The all three kinds time-dependently, PGlcUA-liposomes could avoid liver-trapping most efficiently. Tumor obvious PEG-liposomes from immediately not GM1-liposomes. Finally, differently charged investigated normal mice. positively containing 1,2-dimyristyloxypropyl-3-dimethyl-hydroxyethyl bromide different that neutral negatively DCP-liposomes. agglutinability serum protein ginding marked, these factors affect high DMRIE-liposomes liver. Non-invasive analysis is beneficial obtaining information about drug delivery, might be by PET.