Atomic layer deposition of γ-Fe2O3 nanoparticles on multi-wall carbon nanotubes for magnetic drug delivery and liver cancer treatment

Multi-wall carbon nanotubes (MWCNTs) were oxidized by a mixed acid (HNO3/H2SO4), following by gamma-Fe2O3 nanoparticle deposition by Atomic Layer Deposition (ALD). After that, the surface was further modified for doxorubicin (DOX) drug loading. The morphology and the surface functional groups of MWCNTs were determined by TEM and FTIR, and the DOX loading on the drug carriers was determined by UV-Vis spectroscopy. The N-2 adsorption/desorption curves illustrated that the gamma-Fe2O3 deposition had little impact on the specific surface area of MWCNTs. Finally, the cytotoxicity of MWCNTs and MWCNTs/gamma-Fe2O3 based drug carriers was investigated and compared. The results showed that gamma-Fe2O3 had negligible impacts on the DOX release from MWCNTs, but its magnetization could be beneficial to the precise magnetic drug delivery.