Doxorubicin-loaded lipid-quantum dot hybrids: Surface topography and release properties

A few studies have attempted to combine the physicochemical versatility offered by the liposome structure with the superior optical characteristics of quantum dots (QD) for the construction of multifunctional nanoparticles. We are reporting the construction of drug-loaded liposome-QD hybrid vesicles (L-QD) by incorporating TOPO-capped, CdSe/ZnS QD into the two types of lipid bilayers: the ‘rigid’ disteroylphosphatidylcholine (DSPC:Chol:DSPE-PEG2000) and a fluid-phase bilayer of egg PC (EPC:Chol:DSPE-PEG2000). Structural characterization of L-QD hybrid vesicles using atomic force microscopy (AFM) revealed that the incorporation of QD took place by hydrophobic self-association within the membranes. The encapsulation of hydrophilic small molecules in the internal aqueous phase of the L-QD hybrids showed different degrees of carboxyfluorescein (CF) release in buffer and serum, depending on the type of lipid used. The presence of QD in the lip id bilayer increased the CF release from EPC fluid bilayer.