Quantitative characterization of the lipid encapsulation of quantum dots for biomedical applications

The water solubilization of nanoparticles is key for many applications in biomedicine. Despite the importance of surface functionalization, progress has been largely empirical and very few systematic studies have been performed. Here we report on the water solubilization of quantum dots using lipid encapsulation. We systematically evaluate the monodispersity, zeta potential, stability, and quantum yield for quantum dots encapsulated with single and double acyl–chain lipids, pegylated double acyl–chain lipids, and single alkyl–chain surfactant molecules with charged head groups. We show that charged surfactants and pegylated lipids are important to obtain monodisperse suspensions with high yield and excellent long-term stability.From the Clinical EditorThis study reports on solubilization of nanoparticles in water, a key, but often neglected aspect for biomedical applications. The authors demonstrate that charged surfactants and PEGylated lipids are important to obtain monodisperse suspensions with high yield and long-term stability.

Graphical AbstractLipid encapsulation is a biomimetic approach to water solubilization of nanoparticles that takes advantage of hydrophobic interactions to drive formation of an outer leaflet. The physicochemical properties of lipid-encapsulated nanoparticles, such as monodispersity, zeta potential, stability, and quantum yield, can be optimized by varying the composition of the lipid layer through combinations of single- and double–acyl chain lipids, pegylated double–acyl chain lipids, and single–alkyl chain surfactant molecules with charged head groups.Figure optionsDownload high-quality image (75 K)Download as PowerPoint slide