Targeted cellular delivery of quantum dots loaded on and in biotinylated liposomes.
We describe the preparation, biophysical characterization, and receptor-mediated cellular internalization of biotinylated lipid particles (BLPs) loaded on the surface and internally with two distinct (colors) of quantum dot (QD) probes. BLPs were formulated with 1.4 and 2.7 mol % PEG-lipids containing either a fusogenic or pH-sensitive lipid to promote bilayer destabilization of endosomal membranes and favor QD cytoplasmic release. The amount of PEG was chosen to provide steric stabilization of the final construct. BLPs were loaded with a red-emitting QD(655) and surface coated with a green-emitting QD(525) conjugated to the epidermal growth factor (EGF) ligand in order to target the epidermal growth factor receptor (EGFR). The targeted and QD labeled BLPs showed strong and selective binding to EGFR-expressing tumor cell line and subsequent internalization. The dual-color QD labeling strategy and colocalization analysis allow prolonged live cell imaging of BLPs and loaded cargo independently, using a single excitation wavelength and simultaneous detection of both QDs. The chemistry of bioconjugation for the EGF ligand, the QDs, and the BLPs in a single lipid particle, involves only biotin-streptavidin interaction without requiring further purification from free EGF-QDs preformed complexes. Coupled with an encapsulated drug, the targeted and QD-labeled BLPs could provide imaging and drug delivery in a single multifunctional carrier.
Sigot
Valeria
V
Laboratory of Cellular Dynamics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Gottingen, Germany.
Arndt-Jovin
Donna J
DJ
Jovin
Thomas M
TM
D000818:Animals; D001665:Binding Sites; D001710:Biotin / Q000737:chemistry*; D019921:Biotinylation; D016466:CHO Cells; D002478:Cells, Cultured; D006224:Cricetinae; D003412:Cricetulus; D016503:Drug Delivery Systems; D004815:Epidermal Growth Factor / Q000737:chemistry; D066246:ErbB Receptors / Q000096:biosynthesis / Q000737:chemistry*; D006801:Humans; D008024:Ligands; D008055:Lipids / Q000138:chemical synthesis / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry*; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry; D045663:Quantum Dots; D013499:Surface Properties
D008024:Ligands; D008055:Lipids; D008081:Liposomes; D011092:Polyethylene Glycols; D004815:Epidermal Growth Factor; D001710:Biotin; D066246:ErbB Receptors