Magnetic multiwalled carbon nanotubes with controlled release of epirubicin: an intravesical instillation system for bladder cancer

Background Traditional intravesical instillation treatment in bladder cancer has limited efficacy, which results in a high frequency of recurrence. Purpose The aim of this study was to report on an epirubicin (EPI)-loaded magnetic multi-walled carbon nanotube (mMWCNTs-EPI) system for intravesical instillation in place of the current formulation. Methods The mMWCNTs-EPI system was formulated with carboxylated MWCNTs, Fe3O4 magnetic nanoparticles, and EPI. Features and antitumor activity of the system were investigated. Results Under the effect of external magnets, the mMWCNTs-EPI system showed sustained release and prolonged retention behavior and better antitumor activity than free EPI. The mMWCNTs-EPI system had higher efficiency in enhancing cytotoxicity and inhibiting proliferation in vitro and in vivo than free EPI. Our studies also revealed the atoxic nature of mMWCNTs. Conclusion These findings suggested that mMWCNTs are effective intravesical instillation agents with great potential for clinical application.