Abstract:

Abstract:Objective To prove the targeting effect of the polymer PEG-b-P(LA-co-DHP) micelles in vivo and provide theoretical basis for targeting therapy of tumor.Methods The biodistribution of rhodamine labeled polymer micelles was studied in H22 liver cancer-bearing mice by flouroscence animal imaging. H22 liver cancer-bearing mice were randomly separated in rhodamine conjugated polymer micelles group and free rhodoamine group. The fluoresence intensities in vivo and in isolated organs were measured 1,3,6,12,24 and 48 h after injection. Results Free rhdoamine faded away quickly through metabolism in organs of body,transferrd by circulation system,while no phenomenon of rhdoamine’s enrichment in tumor ocurred. After injected micelles  rhdoamine into body,the concentration of drug in the body was increased slowly. The phenomenon of drug enrichment occured in the tumor 3 h after administration,and  the maximal  concentration was found 6 h after administration,which was higher than any other organs of the body.The concentration remained comparatively higher level  after 12 h,and rhdoamine still stacked in the tumor after 24 h. Conclusion The PEG-b-P(LA-co-DHP) micelles can control the release of its bioconjugated drug in vivo,prolong the biological half-life,and improve the tumor targeting effect of the drug.

Key words: H22 liver cancer-bearing mice； PEG-b-P(LA-co-DHP)；micelles;en
hanced permeability and retention effect；passive targeting