Characterization of Cer-RUB nanomicelles. A, C6-Cer was encapsulated in RUB, forming Cer-RUB complex (Cer/RUB, 1:20 w/w). B, Solubility of Cer-RUB vs. Cer. Compared with C6-Cer (0.1 mg/ml, Left), Cer-RUB (2.0 mg/ml, Right) was dispersed and completely dissolved in RPMI-1640 medium. C, Transmission electron microscopy of Cer-RUB nanomicelles (70,000 magnification). TEM images revealed the average diameter of the nanomicelles is 32±4 nm in water.