Transferrin-modified PLGA nanoparticles significantly increase the cytotoxicity of paclitaxel in bladder cancer cells by increasing intracellular retention

To improve the anticancer effects of paclitaxel (Tax) on bladder cancer, transferrin-modified and unmodified poly(d,l lactide-co-glycolide) nanoparticles (NPs) were generated to deliver Tax. The characteristics of the NPs and the drug-release profiles were evaluated. The cytotoxicity levels of blank NPs and Tax-loaded NPs in the bladder cancer cell lines MBT-2, J-82, and TCC Sup were determined. The uptakes and retentions of the NPs by the cell lines and the intracellular distribution of the NPs were also studied. The results showed similar NPs characteristics and drug-release profiles for NPs with and without transferrin modification. The sizes of NPs with and without transferrin modification were 206 and 278 nm, respectively; the Z-potentials were −23.5 and −24.3 mV, respectively; the drug loadings were 6.5 and 6.7 % w/w, respectively. No cytotoxicity was observed in the bladder cancer cells exposed to blank NPs. Both types of Tax-loaded NPs, however, had significantly higher cytotoxicity levels compared with the Tax solution in the bladder cancer cells. The transferrin-modified, Tax-loaded NPs were significantly more cytotoxic than the Tax-loaded NPs without modification in the MBT-2 and TCC Sup cells. There were no significant differences in NP uptakes between transferrin-modified and unmodified NPs in any of the three studied bladder cancer cell lines; however, the retentions of the modified NPs were significantly higher in the MBT-2 and TCC Sup cells. These findings suggest that NPs can significantly improve the anticancer effect of Tax in bladder cells. Furthermore, transferrin-modified NPs can improve the anticancer effect by increasing intracellular retention and not by increasing uptake. The transferrin-modified NPs are promising drug delivery vehicle for bladder cancer treatment.