Encapsulation of CdSe/ZnS Quantum Dots in Poly(ethylene glycol)-Poly(D,L-lactide) Micelle for Biomedical Imaging and Detection

Abstract: Luminescent CdSe/ZnS QDs, with emission in the red region of the spectrum, were synthesized and encapsulated in poly(ethylene glycol)-poly(D,L-lactide) diblock copolymer micelles, to prepare water-soluble, bio-compatible QD micelles. PEG-PLA diblock copolymers were synthesized by ring opening polymerization of D,L-lactide, in the presence of methoxy PEG as a macroinitiator. QDs were encapsulated with PEG-PLA polymers using a solid dispersion method in chloroform. The resultant polymer micelles, with encapsulated QDs, were characterized using various analytical techniques, such as UV-Vis measurement, light scattering, fluorescence spectroscopy, trans-mission electron microscopy (TEM) and atomic forced microscopy (AFM). The polymer micelles, with encapsu-lated QDs, were spherical and showed diameters in the range of 20-150 nm. The encapsulated QDs were highly luminescent, and have high potential for applications in biomedical imaging and detection