Abstract
Objective: A multifunctional tumor-targeting drug delivery system employing single-walled carbon nanotubes (SWCNT) as drug carriers, AS1411 as targeting ligand and doxorubicine (DOX) as a model chemotherapy drug was constructed. Methods: Firstly, SWCNT were modified with F68 (4.0 mg/ml) by ultrasonic dispersing technology due to the action of hydrophobic force and Van der Waals force, endowing SWCNT water dispersions and biocompatibility. Meanwhile, DOX could be easily absorbed on the surface of SWCNT by the π-π stacking, electrostatic adsorption and hydrophobic interactions. Finally, AS1411 was attached to the surface of DOX-SWCNT by the π-π stacking and electrostatic adsorption to obtain a tumor-targeting delivery system. Cellular uptake, anti-tumor effect in vitro and in vivo, cell cycle and apoptosis and biodistribution of AS1411-DOX-SWCNT were investigated, compared with the DOX solution. Conclusion: This AS1411-mediated DOX-loaded SWCNT (AS1411-DOX-SWCNT) delivery system not only retained both optical properties of SWCNT and cytotoxicity of DOX but also could accumulate in tumors, which facilitated combination of chemotherapy and photothermal therapy. AS1411-DOX-SWCNT could effectively promote DOX cellular uptake and then increase intracellular accumulation as a targeting delivery system. AS1411-DOX-SWCNT by NIR laser excited could trigger S phase arrest and the late stage apoptotic on PC3 cancer cells. The investigation in vivo further confirmed that this system possessed higher tumor targeting capacity and antitumor efficacy than DOX, especially with NIR laser irradiation.
Keywords: Aptamer, chemo-photothermal synergistic effect, single-walled carbon nanotubes, tumor-targeting.