Dendrimers and their less well-defined : cousins hyperbranched polymers; are widely investigated as scaffold materials in tissue: engineering,;as drug delivery agents, and in diagnostic imaging applications. Despite the large interest of using these unique materials' as,polymer-based : applications, a clear understanding of the cellular Uptake and transport of these: polyester-based nanoparticles is still lacking. The objective of this study is to evaluate the cellular uptake profiles and intracellular trafficking of polymer micelles:;. built from the hyperbranched polyester Bottom,. fitted With poly(ethylene,glycol) and fluorescent groups in MDA-MB468 breast cancer cells. Results Show that,the uptake of these nanoparticles correlated positively to both time and Concentration and that the uptake of the nanoparticles was energy dependent. I These: polyesterbased nanoparticles appear to translocate across cells via. clathrin and macropinocytosis-mediated endocytosis. Observations of the intracellular trafficking of the nanoparticles indicate that particles could be released from early endosomes after being internalized, and the:particles exhibit perinuclear localization: The uptake behavior Of the nanoparticles was further evaluated in a range of cell lines. These results,allow the generation of the knowledge base required to design polyester-based nanocarriers that can be used efficiently and specifically for drug delivery applications and imaging applications.