Gd dtpa bma

F3-PLGA@MB/Gd was prepared as follows: First, 0.1 mL MB (5 mg/mL, 5 mg MB dissolved in 1 mL ddH2O, Sigma-Aldrich China) and 0.1 mL Gd-DTPA-BMA (287 mg/mL, GE Healthcare Ireland) were added to 3 mL CH₂CL₂ containing 50 mg dissolved MAL-PEG-PLGA-F3 and 6 mg dissolved MB. The sufficiently dissolved mixture was emulsified using an ultrasonic oscillator (SONICS & MATERALS Inc., USA) at 100 W for 180 s. Subsequently, the above solution was decanted into 10 mL poly vinyl alcohol (PVA, MV=25 000, Sigma) solution (4% w/v) for the second emulsion by an ultrasonic oscillator at 50 W for 90 s. Next, the emulsion was stirred at room temperature for 2~5 h to extract CH₂CL₂. The supernatants were discarded after centrifugation at 10,000 rpm for 5 min, and the precipitate was suspended in 2 mL ddH2O. Centrifugation and generation of the suspension were performed three times.