A new PEG-lipid conjugate micelle for encapsulation of CdSe/ZnS quantum dots.

A new polymer conjugate of poly(ethylene glycol) (PEG) and 10,12-pentacosadiynoic acid (PCDA), PEG-PCDA conjugate, was synthesized by coupling reaction between carboxyl group of PCDA and hydroxyl group of PEG. Luminescent CdSe/ZnS QDs were encapsulated in the polymer micelles of mixtures of PEG-PCDA and PCDA using solid dispersion method to prepare water-soluble and biocompatible QD micelles. Upon UV-irradiation, the core of QD micelles was further stabilized by intramicellar crosslinking between neighboring PCDA moieties. The polymer conjugate was characterized by 1H-NMR, FT-IR, and GPC measurements, and thereof QD micelles observed using transmission electron microscopy (TEM) and dynamic light scattering (DLS). The QD micelles were spherical with diameters in the range of 30-190 nm. The encapsulated QDs in polymer micelles are water-soluble and have the high potential for applications in biomedical imaging and detection due to their good colloidal stability and biocompatible surface.