Structurally engineered anodic alumina nanotubes as nano-carriers for delivery of anticancer therapeutics

Here, we report a study on the biocompatibility, cell uptake and in vitro delivery of tumor necrosis factor-related apoptosis-inducing ligand (Apo2L/TRAIL) by new nano-carriers called anodic alumina nanotubes (AANTs) for potential cancer therapy. AANTs were electrochemically engineered by a unique pulse anodization process, which enables precise control of the nanotube geometry, and used here as nano-carriers for drug delivery. In vitro cytotoxicity and cell uptake of AANTs was assessed using MDA-MB231-TXSA human breast cancer cells and mouse RAW 264.7 macrophage cells. AANTs exhibited excellent biocompatibility in both cell lines over a time course of five days even at a maximum concentration of AANTs of 100 μg mL−1. Transmission electron microscopy and fluorescence microscopy confirmed a significant uptake of AANTs by RAW 264.7 cells and breast cancer cells. AANTs loaded with the pro-apoptotic protein Apo2L/TRAIL showed exceptional loading capacity (104 ± 14.4 μg mg−1 of AANTs) and demonstrated significant decrease in viability of MDA-MB231-TXSA cancer cells due to apoptosis induction. These results demonstrate that AANTs are promising nano-carriers for drug delivery applications.