The obtained PS-QD micellar suspension was further purified to remove excess PLs by overnight dialysis against phosphate buffer (PBS) saline using a 100-kD

dialysis cutoff membrane. Table 1 Preparation and physico-chemical characteristics of PS-QD micelles   Polar lipids (mg) PS (mg) QD (620 nm; 2-μM concentration) Clarity of emulsion Stability of flourescence Average size (by intensity; in nm) Polydispersity index (PDI) Zeta potential charge (in mV) QD-PEG-PS mole ratio DSPE-PEG (2000) methoxy                 100:0, PS (0) 4.5 – 0.2 nmol Clear Quenched after 45 days 198.3 0.24 -8.7   60:40, PS (40) 2.7 1.8 0.2 nmol Clear Stable 104.6 0.18 -16.4   50:50, PS (50) 2.25 2.25 0.2 nmol Clear Stable 40.9 0.14 -14.5   40:60, PS Selleck OSI-027 (60) 1.8 2.7 0.2 nmol Hazy BTSA1 order Stable 143.0 0.16 -21.8   0:100, PS (100) – 4.5 0.2 nmol Hazy Stable 127.3 0.22 -32.2 QD-PEG-COOH DSPE-PEG (2000) carboxylic acid                 4.5 – 0.2 nmol Clear Stable 60.1 0.22 -25.3 Physico-chemical characterization of PS-QD micelles

The mean hydrodynamic diameter, polydispersity index and zeta potential charge of PS-QD micelles was Cilengitide manufacturer measured using a Zeta Nanosizer ZS (Malvern Instruments Ltd, Worcestershire, UK; Table 1). For size measurements, the PS-QD micelles were diluted (1:100) in 100-mM PBS buffer and for zeta potential measurements the PS-QD micelles were diluted (1:1,000) in 10-mM PBS buffer. All samples were measured in triplicate. The morphology of PS-QD micelles was analyzed by transmission electron aminophylline microscopy (TEM; JEM1010; JEOL, Tokyo, Japan) operating at 60kV. For the preparation of PS-QD micelles for TEM, PS-QD micelles were diluted in distilled water and dropped on Formvar-coated copper

grids. Samples were examined with and without negatively staining with osmium tetroxide. In vitro stability of PS-QD micelles The colloidal stability of PS-QD micelles was analyzed by incubating PS-QD micelles in cell culture medium containing 10% fetal bovine serum (FBS). Four-hundred microliters of PS-QD micelles (QD concentration 1 μM) were diluted in 800 μL of cell culture media and placed in a 37°C water bath for 24 h. After 24 h, 0.5 mL of the micelle solution in media was diluted twice with PBS buffer (0.1M) for particle size analysis using a Zeta Nanosizer ZS. In vitro cell uptake (fluorescence microscopy and flow cytometry studies) The cellular uptake and distribution of PS-QD micelles were semiquantitated by fluorescence microscopy and flow cytometry. After the J774A.1 cells reached 80% confluency, the cells were detached by a scraper and seeded onto a 6-well plate at a density of 2 × 104 cells per well and incubated overnight.