Integration of polyethylenimine functionalized carbon nanotubes nanocarriers for efficient DNA delivery

Optically active nanocarrier has shown great application prospects in cancer photothermal and gene therapy. However, monotherapy has many side effects and limited therapeutic effect, and the combination therapy with high anti-cancer efficiency has become the current research trend. We reported a facile chemical grafting strategy to construct a combination of photothermal and gene therapy nanocarrier system through amide reaction. Carbon nanotube (CNTs) undergo acid oxidation to introduce -COOH groups, followed by grafting polyethyleneimine (PEI) onto the CNTs-COOH through acylation to obtain CNTs-PEI10k and CNTs-PEI25k, which exhibited superior dispersibility compared to CNTs. As expected, the diameters of CNTs-PEI10k and CNTs-PEI25k were 165.2 nm and 266.6 nm, respectively. When exposed to 808 nm near-infrared light (0.5 W/cm²), CNTs-PEI10k and CNTs-PEI25k exhibited strong photothermal. At a carrier concentration of 40 μg/mL, the survival rates of HepG2 and MCF-7 cells were both below 10 %, confirming their effectiveness in cancer cell treatment. In vitro experiments showed that CNTs-PEI10k/DNA and CNTs-PEI25k/DNA had transfection efficiencies of 47.44 % and 54.56 % in HeLa cells. This work combined gene and photothermal therapy to construct a promising gene delivery carrier with low toxicity and high transfection efficiency, which laid the foundation for the development of low toxicity and high efficiency gene delivery carrier.