The efficacy of methotrexate-impregnated hydroxyapatite composites on human mammary carcinoma cells.

PURPOSE To investigate the efficacy of local biodegradable composites of hydroxyapatite, plaster of Paris, and a binder of either alginate or chitosan impregnated with methotrexate on human mammary carcinoma cells. METHODS An in vitro analysis of drug dissolution and a cytotoxicity test on human mammary carcinoma cells were performed over one month. Physicochemical properties of each composite were investigated using scanning electron microscopy, X-ray diffractometry, and Fourier transform infrared spectroscopy. RESULTS Both composites with a binder of either alginate or chitosan could release methotrexate for over one month. The amount of methotrexate released depended on the amount of methotrexate loaded. The composite using alginate as a binder released a significantly greater amount of methotrexate than that using chitosan as a binder (p<0.05). The elution of both composites showed favourable cytotoxicity when the concentration was greater than 5 microg/ml. CONCLUSION Methotrexate-impregnated hydroxyapatite composites appear to be effective local skeletal methotrexate delivery systems against human mammary carcinoma cells in an in vitro model.