Adsorption and release behavior of epirubicin hydrochloride on carboxylated single-walled carbon nanotubes

In this study, the adsorption behavior of epirubicin hydrochloride (EPI) on carboxylated single- walled carbon nanotubes (c-SWNTs) obtained by mixture acid treatment was investigated. The results indicated that the dispersion of c-SWNTs in water was obviously improved. The absorption of EPI on c-SWNTs came to equilibrium after 240 min and could be explained by pseudo-second-order model. Moreover, there were heterogeneous distribution of active sites onto c-SWNTs surface and the Freundlich isotherm model was better fit to describe the absorption precess of EPI on c-SWNTs. The absorption capacity of EPI on c-SWNTs increased obviously with the increasing pH and decreasing temperature. Compared with multi-walled carbon nanotubes, carboxylated multi-walled carbon nanotubes, SWNTs, c-SWNTs possessed higher absorption capacity for EPI. The controlled, targeted and sustained release of EPI from c-SWNTs-EPI could be instructive for the development of nano-carrier.