Gadolinium(III) (1,4,7,10-tetraazacyclododecane)-1,4,7,10-tetraacetate (Gd-DOTA) was purchased from Marcocylics (Dallas, TX). 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycerol)-2000] ammonium salt (DSPE-PEG2000) was purchased from Avanti Polar Lipids, Inc. (Alabaster, AL). Doxorubicin hydrochloride (DOX) was from Sigma (St. Louis, MO). Sodium Acetate-d3, D2O(99.9% atom %D), 3-(Trimethylsilyl) propionic-2,2,3,3,-d4 sodium (TSP) and 3-(Trimethylsilyl)-1-propanesulfonic sodium (DSS) were purchased from Aldrich (St. Louis, MO). The water used in this work was generated from Milli-Q system (Millipore Corporation, Danvers, MA).