Efficacy and biodistribution of tocopheryl polyethylene glycol succinate noncovalent functionalized single walled...

The aim of this study is to develop the noncovalent functionalized single walled nanotubes loading doxorubicin. A tocopheryl polyethylene glycol succinate (TPGS) noncovalent modification of single walled carbon nanotubes (SWNTs) loading antitumor agent doxorubicin (Dox) via the physical absorption was developed. Dox was successfully loaded onto the surface of carbon nanotubes (loading amount was 168.7 microg/ml), which was confirmed by UV-vis-NIR absorbance spectra and dynamic light scattering assay. ICR mice bearing mouse sarcoma tumor were subjected to intratumoral injection of TPGS-SWNTs-Dox. Based on the in vivo antitumor activities of the locally injected the formulation into the tumor bearing mice, it was shown that there was modest (up to 50.2%) delay of tumor growth compared with the groups receiving no treatment, which was better than free dox (up to 40.2%). The biodistribution studies demonstrated that there were the longest retention time in tumor, the highest tumor accumulation, as well as less accumulation in other solid tissues, especially in heart, when tumor bearing mice were administered with TPGS-SWNTs-Dox. It may be attributed to the enhanced permeability and retention (EPR) effect of TPGS-SWNTs-Dox. The histopathological findings revealed that the new carbon nanomaterials were a safe vehicle for topical drug delivery systems. These results suggested that the noncovalent modification of carbon nanotubes by TPGS for anticancer agents may be a promising strategy for cancer treatment.