Drug‐Ceramic 2‐Dimensional Nanoassemblies for Drug Delivery System in Physiological Condition
The anticancer drug methotrexate (MTX) was successfully incorporated into the layered ceramic nanoparticles of layered double hydroxides (LDHs). The prepared MTX‐LDH two‐dimensional nanoassemblies
showed enhanced chemical and thermal stability of intercalated MTX molecules through the effective electrostatic interaction with ceramic LDH layers. And the surface charge of MTX‐LDHs was determined
to be highly positive whereas that of MTX is fairly negative. The anticancer effect of MTX‐LDH compared with MTX was evaluated in the human osteosarcoma cell culture line SaOS‐2, showing much
faster drug efficacy with low concentration. The time‐dependent cellular uptake of MTX determined by high performance liquid chromatography showed the much enhanced cellular drug concentration of MTX‐LDH treated cancer
cells than the MTX treated ones. The particle size of MTX‐LDH nanoassemblies was estimated in various solutions such as saline, phosphate saline, and RPMI 1640 cell culture medium, showing that the hydrodynamic
size maintains at ~100 nm, regardless of the suspension media. The positive surface charge and ~100 nm size of MTX‐LDHs is considered to be the major factor in the high cellular uptake and enhanced drug efficacy.