PEGylated Carbon Nanotubes Decorated with Silver Nanoparticles: Fabrication, Cell Cytotoxicity and Application in Photo Thermal Therapy

A new technique for cancer therapy is Photo Thermal Therapy (PTT). In the PTT technique, photon energy is converted into heat via various operations to destroy malignant tumors. Carbon nanotubes (CNTs) have good optical absorption in the near-infrared (NIR) spectrum and could transform optical energy into heat to induce hyperthermia in the PTT method. In this study, CNTs were firstly oxidized (O-CNT) and then decorated with silver nanoparticles (Ag NPs). Polyethylene glycol (PEG) was utilized for wrapping the surface of CNTs (O-CNT/Ag-PEG). Coating of CNTs with Ag NPs and PEG was confirmed by XRD, FESEM, and TEM techniques. Results demonstrated that noble metal could increase optical absorption of CNTs and concurrently improve the efficacy of the PTT technique. Cell cytotoxicity study showed that O-CNT/Ag NPs were less cytotoxic than O-CNTs, and O-CNT/Ag-PEG had the lowest toxicity against HeLa, HepG2, and PC3 human cell lines. The efficacy of O-CNT/Ag-PEG NPs in destroying malignant melanoma tumors was evaluated through the PTT technique. A continuous wave NIR laser diode (λ = 808 nm, P = 2 W, and I = 2 W/cm(2)) irradiated the tumor sites for 8 min once in the period of the treatment. The tumors in cases receiving O-CNT/Ag-PEG were shrunk efficiently compared to laser treatment ones. Results of in-vivo studies demonstrated that O-CNT/Ag-PEG was a puissant candidate in extirpating malignant tumors in PTT method.