PAMAM-Conjugated Alumina Nanotubes as Novel Noncytotoxic Nanocarriers with Enhanced Drug Loading and Releasing Performances

Alumina nanotubes are surface-conjugated with polyamidoamine (PAMAM) dendrimers of the third generation, aimed at obtaining novel nanomaterials for drug delivery applications. The structure and surface properties of PAMAM-conjugated alumina nanotubes (PAMAM-Al₂O₃NT) are characterized using Fourier Transform Infrared spectroscopy, solid state ¹³C-RMN, transmission electron microscopy, N₂ adsorption–desorption isotherms, X-ray powder diffraction (XRD), and thermogravimetric analysis (TGA), which supported for a 3.0 wt% of PAMAM grafting in the prepared product. The drug loading and releasing properties of PAMAM-Al₂O₃NT are examined using three model therapeutic compounds, namely, curcumin, methotrexate, and silibinin, showing that PAMAM conjugation enhances the drug loading capacity and drug-adsorbent affinity compared to pristine Al₂O₃NT systems. Additionally, Alamar Blue cell viability assays reveal that PAMAM-Al₂O₃NT are not cytotoxic materials over a wide concentration range. These results suggest that PAMAM–Al₂O₃NT are potential nanostructured vehicles for drug delivery applications. (Figure presented.).