Tumor-imaging potential of liposomes loaded with In-111-NTA: biodistribution in mice.
EMT6 tumors in BALB/c mice have been successfully imaged with small (less than 0.1 mu), unilamellar lipid vesicles (SUVs) loaded with In-111 nitrilotriacetic acid (In-111 NTA). Neutral SUVs prepared from distearoyl phosphatidylcholine (DSPC) and cholesterol (CH) (ratio 2:1) delivered sufficient radioactivity to allow tumor visualization 24 hr after i.v. injection; so did positively and negatively charged SUVs with the ratio 4:1:1 for DSPC:CH:X, were X was stearylamine or dicetyl phosphate. Other SUVs containing a 6-aminomannose or 6-aminomannitol derivative of cholesterol did not cause significant tumor accumulation of In-111 NTA, and tumor images were not readily discernible. The maximum tumor-associated radioactivity, 18.5% of injected dose per gram of tissue, was achieved with neutral SUVs. This level of tumor-associated In-111 was over 4 times that observed when unencapsulated In-111 NTA was injected. Neutral SUVs also gave the lowest specific activities in the liver and spleen (14.6% and 18.8% of dose respectively).
D000085:Acetates; D000818:Animals; D002460:Cell Line; D007204:Indium; D008081:Liposomes / Q000008:administration & dosage*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000000981:diagnostic imaging*; D009571:Nitrilotriacetic Acid / Q000378:metabolism; D011868:Radioisotopes; D011877:Radionuclide Imaging; D013997:Time Factors; D014018:Tissue Distribution
D000085:Acetates; D008081:Liposomes; D011868:Radioisotopes; D007204:Indium; D009571:Nitrilotriacetic Acid