Biodistribution of phospholipid vesicles in mice bearing Lewis lung carcinoma and granuloma.

Murine biodistributions of vesicle-encapsulated [111In]NTA were obtained under a number of conditions. These included normal animals, those bearing s.c.- or i.v.-implanted Lewis Lung Carcinoma (LLC) and those having both s.c.-LLC and sterile granuloma. Variations in the distributions were observed with a preinjection of unlabeled aminomannose (AM) vesicles or an increase in the labeled vesicle size. It was found that s.c. LLC exhibited uptake of between 10 and 25% injected dose/g (% ID/g) depending upon tumor mass with larger lesions having lower accumulation. Significant uptake enhancement (p less than 0.05) occurred after AM blockade. Similar results hold for the i.v.-injected LLC cells implying targeting to both primary and metastatic sites. By increasing vesicle size by a factor of 4, uptake by s.c. LLC declined to essentially blood levels; e.g., 2% ID/g. Granuloma accumulations were also at circulating values and, unlike s.c. LLC, could not be imaged.