The purpose of this study was to observe and analyze the effect of Methotrexate-Layered Double Hydroxide (LDH) hybrids on growth inhibition and the apoptosis of human osteosarcoma cell lines (SaOS-2, MG-63) and normal fibroblasts.

FITC-LDH hybrids were added to the cells and incubated for 2, 4, 6, and 8 hours. The samples were examined by fluorescence microscopy. SaOS-2 and MG-63 cells, and a normal fibroblast cell line (Detroit 551) were treated with 500 g/mL MTX and 500 g/mL MTX-LDH hybrids for 24, 48, 72, and 96 hours, respectively. The proliferation was measured by using the MTT assay. Apoptosis was determined by DNA fragmentation analysis.

The hybrids with LDH entered the cells effectively in a time- and dose-dependent manner. The proliferation of SaOS-2 cells in a culture treated with 500 g/mL of MTX-LDH hybrids for 24 hours was significantly inhibited (37% more) compared to those treated with MTX. MG-63 cell growth was inhibited 20% more than SaOS-2 cell growth. However, the difference in the degrees of inhibition of cells treated with MTXLDH hybrid or with MTX alone reduced with time. DNA ladders appeared in cells treated with 500 g/mL MTX-LDH hybrid for 24 hours but not in those treated with MTX and LDH alone.

The results of this study suggest that MTX-LDH hybrid more effectively enters cells and inhibits their proliferation than MTX alone.