Effect of Doxorubicin Release Rate From Polyethylene Glycol-Modified Liposome on Anti-tumor Activity in B16-BL6 Tumor-Bearing Mice

To investigate the effect of doxorubicin (DOX) release rates from polyethylene glycol (PEG)-liposomes on the anti-tumor activity, several in-vitro and in-vivo studies were performed by utilizing three types of DOX-PEG-liposomes showing the slow (L-Slow), middle (L-Mid) and fast (L-Fast) release rates of DOX. L-Mid provided the highest anti-tumor activity in B16-BL6 tumor-bearing mice, although the largest amount of DOX distribution into the tumor tissue was observed in L-Slow-administered mice and the lowest was in L-Fast-administered mice. To elucidate the reason for this discrepancy, DOX distribution into cancer cells constituting the tumor tissue was determined and the highest DOX distribution into cancer cells was observed in L-Midadministered mice. These results clearly indicate that the adequate drug release rate from liposome should make it possible to deliver the substantial amounts of drugs into cancer cells, leading to the actual anti-tumor activity. (C) 2021 American Pharmacists Association. Published by Elsevier Inc. All rights reserved.

Automated summary

The effect of doxorubicin release rates from PEG-liposomes on anti-tumor activity was investigated. The study showed that liposomes with a moderate release rate exhibited the highest anti-tumor activity, which was correlated with the distribution of the drug in cancer cells.