title: Polymersomes containing quantum dots for cellular imaging.
abstract: Quantum dots (QDs) are highly fluorescent and stable probes for cellular and molecular imaging. However, poor intracellular delivery, stability, and toxicity of QDs in biological compartments hamper their use in cellular imaging. To overcome these limitations, we developed a simple and effective method to load QDs into polymersomes (Ps) made of poly(dimethylsiloxane)-poly(2-methyloxazoline) (PDMS-PMOXA) diblock copolymers without compromising the characteristics of the QDs. These Ps showed no cellular toxicity and QDs were successfully incorporated into the aqueous compartment of the Ps as confirmed by transmission electron microscopy, fluorescence spectroscopy, and fluorescence correlation spectroscopy. Ps containing QDs showed colloidal stability over a period of 6 weeks if stored in phosphate-buffered saline (PBS) at physiological pH (7.4). Efficient intracellular delivery of Ps containing QDs was achieved in human liver carcinoma cells (HepG2) and was visualized by confocal laser scanning microscopy (CLSM). Ps containing QDs showed a time- and concentration-dependent uptake in HepG2 cells and exhibited better intracellular stability than liposomes. Our results suggest that Ps containing QDs can be used as nanoprobes for cellular imaging.
authors.affiliation: Division of Pharmaceutical Technology, University of Basel, Basel, Switzerland.
authors.forename: Marine
authors.initials: M
authors.lastname: Camblin
authors.affiliation: Division of Pharmaceutical Technology, University of Basel, Basel, Switzerland.
authors.forename: Pascal
authors.initials: P
authors.lastname: Detampel
authors.affiliation: Division of Pharmaceutical Technology, University of Basel, Basel, Switzerland.
authors.forename: Helene
authors.initials: H
authors.lastname: Kettiger
authors.affiliation: Department of Chemistry, University of Basel, Basel, Switzerland.
authors.forename: Dalin
authors.initials: D
authors.lastname: Wu
authors.affiliation: Division of Pharmaceutical Technology, University of Basel, Basel, Switzerland.
authors.forename: Vimalkumar
authors.initials: V
authors.lastname: Balasubramanian
authors.affiliation: Division of Pharmaceutical Technology, University of Basel, Basel, Switzerland.
authors.forename: Jörg
authors.initials: J
authors.lastname: Huwyler
mesh_terms: D058948:Cell Tracking / Q000379:methods*; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis; D056945:Hep G2 Cells; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D018613:Microscopy, Confocal / Q000379:methods*; D053769:Nanocapsules / Q000737:chemistry* / Q000648:ultrastructure*; D010080:Oxazoles / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D045663:Quantum Dots; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013347:Subcellular Fractions / Q000648:ultrastructure*
chemical_list: D020099:Coated Materials, Biocompatible; D053769:Nanocapsules; D010080:Oxazoles; D011108:Polymers; C542789:poly(2-methyl oxazoline)-block polydimethylsiloxane-block-poly(2-methyl oxazoline)
keywords: cellular imaging; cellular uptake; polymersomes; quantum dots