Effect of intratumoral injection on the biodistribution and therapeutic potential of novel chemophor EL-modified single-walled nanotube loading doxorubicin.

The purpose of this study is to evaluate in vivo efficacy and loco-regional distribution of a doxorubicin (DOX)-loaded Polyoxyl 35 Castor Oil (Cremophor EL, CrEL) noncovalent modified single-walled carbon nanotubes (SWNTs) formulation in a sarcoma tumor model after intratumoral injection. The drug loaded SWNTs were successfully prepared via physical absorption, which was confirmed by UV-vis-NIR absorbance spectra and dynamic light scattering assay. Solid tumor models were obtained by injecting mouse sarcoma 180 cells into the thighs of ICR mice. CrEL-SWNTs-DOX, CrEL-SWNTs, free DOX and saline (control) were intratumorally injected after 5 days post transplantation. The biodistribution studies demonstrated that intratumoral delivery of CrEL-SWNTs-DOX resulted in longer drug retention time in tumor, higher tumor level (27.6-fold than that of free DOX), as well as less accumulation in other solid tissues, especially in heart. Furthermore, in vivo anti-tumor activity results showed that CrEL-SWNTs-DOX could effectively suppress the tumor growth than free DOX and the control, attributing to its enhanced intratumoral DOX level. The histopathological findings revealed that the new carbon nanomaterials were a safe vehicle for topical drug delivery systems. It is concluded that this noncovalent modification of carbon nanotubes by CrEL for anticancer agents might be a promising alternative for cancer treatment.