The performance of attapulgite hybrids combined with MTX and Au nanoparticles

Methotrexate (MTX) conjugated with attapulgite clay (ATP), ATP/MTX, was successfully synthesized by using MTX as a guest molecule and natural ATP as a kind of drug carrier, where MTX was intercalated and adsorbed onto the channel and surface of ATP in acidic aqueous solution. Furthermore, Au nanoparticles were bound onto the surface of ATP to form tubelike ATP-Au nanocomposites by electrostatic force. These nanocomposites exhibit similar localized surface plasmon resonance absorption characteristics to those of Au nanorods with a longitudinal absorption mode that shifts to the near-infrared (NIR) region (∼670 nm). The results indicated that the addition of MTX had no effect on the morphology of ATP, and the drug-loading efficiency of ATP was measured as 22.36%. Results of MTT bioassay and cell morphology analysis revealed that while ATP did not kill human cervical cancer cells (Hela), ATP/MTX nanocomposites had a good inhibitory effect on them.