A green process of polyampholyte-grafted single walled carbon nanotubes for enhanced anticancer drug delivery

Abstract

Polyampholytes are polymers including modified groups that can exhibit both a negative and a positive charge is wide attention for application in multidisciplinary fields such as biochemistry, biomaterials and pharmaceutical. In this dissertation, we report a novel process for surface modified single-walled carbon nanotubes (SWCNTs) as drug nanocarriers by using facile and green synthetic methods. Firstly, polyampholytic alternating polymers having furfuryl amine and 3-(dimethylamino)-1-propylamine as functional groups were prepared via one-pot thiol-ene chemistry in sustainable conditions. The monomer was prepared by the conjugation between maleic anhydride and thiolactone. Then, the polyampholytes were synthesized by one-pot two-step reaction through the amine-thiol-ene “click” chemistry. The alternating polymers were characterized by proton nuclear magnetic resonance (1H NMR) and Fourier-transform infrared spectroscopy (FTIR). The anti-fouling of polyampholytes were performed and investigated by Ultraviolet–visible spectroscopy (UV-Vis). Furthermore, the obtained polymers were then used to a direct functionalization onto the surface of SWCNTs through Diels-Alder click reaction conducted in aqueous media under ultrasonication. The resulting hybrid was characterized by FT-IR, Thermogravimetric analysis (TGA), Raman spectroscopy and UV-vis measurements. The hybrid improved the drug loading content up to 150 wt.%, indicating that they are potential doxorubicin (DOX) delivery nano-vehicles. Moreover, the in-vitro drug release profiles showed that there was a burst release of DOX at pH 5.5 under an acidic condition in microenvironment of tumor cells, in contrast with a lower release rate at pH 7.4 in the physiological condition. Significantly, we believe that the new facile grafting process approach can be reduced the using of organic solvent in preparation of drug nanocarriers.