ABCB1 and neoplasm: Co-administration of Paclitaxel (20 mg/kg) and C6-ceramide (100 mg/kg) in poly(ethylene oxide)-modified poly(epsilon-caprolactone) nanoparticles revealed > 4.3- and 3-fold increase in tumor growth delay and 3.6- and 3-fold increase in tumor volume doubling time in wild-type SKOV-3 and multidrug resistant (MDR-1 positive) SKOV-3TR models respectively compared to individual agents (Devalapally et al., 2007).