Novel doxorubicin loaded PEGylated cuprous telluride nanocrystals for combined photothermal-chemo cancer treatment

Recently, combined photothermal-chemo therapy has attracted great attention due to its enhanced anti-tumor efficiency via synergistic effects. Herein, PEGylated cuprous telluride nanocrystals (PEGylated Cu₂Te NCs) were developed as novel drug nanocarriers for combined photothermal-chemo treatment of cancer cells. PEGylated Cu₂Te NCs were fabricated through a simple two-step process, comprised of hot injection and thin-film hydration. The as-prepared PEGylated Cu₂Te NCs (average diameter of 5.21±1.05nm) showed a noticeable photothermal conversion efficiency of 33.1% and good capacity to load hydrophobic anti-cancer drug. Due to the protonated amine group at low pH, the doxorubicin (DOX)-loaded PEGylated Cu₂Te NCs (PEGylated Cu₂Te-DOX NCs) exhibited an acidic pH promoted drug release profile. Moreover, a three-parameter model, which considers the effects of drug-carrier interactions on the initial burst release and the sustained release of drug from micro- and nano-sized carriers, was used to gain insight into how pH and laser irradiation affect drug release from PEGylated Cu₂Te-DOX NCs. Based on the results from in vitro cell study, PEGylated Cu₂Te-DOX NCs revealed remarkably photothermal-chemo synergistic effect to HeLa cells, attributed to both the PEGylated Cu₂Te NCs mediated photothermal ablation and enhanced cellular uptake of the drug. Thus, our results encourage the usage of Cu₂Te-DOX drug nanocarriers for enhanced treatment of cancer cells by combined photothermal-chemo therapy.