| Abstract
| - A star polymer composed of amphiphilic block copolymer arms has been synthesized and characterized.The core of the star polymer is polyamidoamine (PAMAM) dendrimer, the inner block in the arm islipophilic poly(ε-caprolactone) (PCL), and the outer block in the arm is hydrophilic poly(ethylene glycol)(PEG). The star-PCL polymer was synthesized first by ring-opening polymerization of ε-caprolactonewith a PAMAM-OH dendrimer as initiator. The PEG polymer was then attached to the PCL terminusby an ester-forming reaction. Characterization with SEC, 1H NMR, FTIR, TGA, and DSC confirmedthe star structure of the polymers. The micelle formation of the star copolymer (star-PCL−PEG) wasstudied by fluorescence spectroscopy. Hydrophobic dyes and drugs can be encapsulated in the micelles.A loading capacity of up to 22% (w/w) was achieved with etoposide, a hydrophobic anticancer drug. Acytotoxicity assay demonstrated that the star-PCL−PEG copolymer is nontoxic in cell culture. Thistype of block copolymer can be used as a drug delivery carrier.
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