Floxuridine coupling with lactosaminated human albumin to increase drug efficacy on liver micrometastases.
BACKGROUND
Conjugates of nucleoside analogues with galactosyl terminating peptides selectively enter hepatocytes through the asialoglycoprotein receptor. After intracellular release from the carrier, the drugs partly exit from hepatic cells into hepatic blood.


OBJECTIVE
To establish whether administration of a conjugate of floxuridine with lactosaminated human albumin selectively enhances drug concentrations in hepatic blood. Floxuridine is a fluoropyrimidine active on human colorectal cancer, a tumour which metastasises first to the liver.


METHODS
In rats injected with free or conjugated floxuridine, plasma levels of the drug were determined in hepatic veins and in inferior vena cava, in order to measure drug concentrations in hepatic blood and in the systemic circulation, respectively.


RESULTS
Ratios between floxuridine levels in hepatic veins and those in systemic circulation were found to be seven times higher in rats injected with the conjugate (p=0.000).


CONCLUSIONS
The present results suggest that coupling to lactosaminated albumin might improve the effect of floxuridine in adjuvant chemotherapy of colorectal cancer by exposing the cells of liver micrometastases (nourished by hepatic sinusoids) to enhanced drug concentrations.
Department of Experimental Pathology, University of Bologna, Italy.
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Di Stefano
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Busi
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Fiume
D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage* / Q000097:blood; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000473:pathology; D004337:Drug Carriers; D016503:Drug Delivery Systems / Q000379:methods*; D005260:Female; D005467:Floxuridine / Q000008:administration & dosage* / Q000097:blood; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008113:Liver Neoplasms / Q000517:prevention & control / Q000556:secondary*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D023421:Models, Animal; D009368:Neoplasm Transplantation; D051381:Rats; D017208:Rats, Wistar; D012709:Serum Albumin / Q000008:administration & dosage*
D000964:Antimetabolites, Antineoplastic; D004337:Drug Carriers; D012709:Serum Albumin; D005467:Floxuridine