*3.4. Targeted Drug Delivery*

The experiments described above support the observation that our bi-HNTs were successfully taken up by colon carcinoma cells (CT26WT). As the bi-HNTs were designed as a drug delivery system, we selected methotrexate (MTX) as model drug and loaded into bi-HNTs. Methotrexate is a commonly used anti-cancer drug to osteosarcoma. However, it is well-known for severe side effects. A cancer target drug delivery system is a promising strategy to reduce side effects and improve drug efficiency.
