*2.15. MTX-bi-HNTs Targeting*

Methotrexate loaded bi-HNTs (50 μg/mL) were co-cultured with CT26WT, K7M2-WT, and MC3T3- E1 pre-osteoblasts separately in 48 wells tissue culture plates (1 <sup>×</sup> 105 cells/well). After 24 h incubation, cell viability of each cell type was assessed by MTS agent as above. Cells cultured without HNTs set as control.
