In vitro cytotoxicity studies of LyAgNP, LyFeNP and LyGNP by using MTT assay

Cell culture Human HT-29 cell, Colo 320 D and Hella celline was maintained in DMEM medium supplemented with 10% fetal bovine serum. The cells were plated at a density of 1 × 1 cells per well in a 96-well plate, and cultured for 24 h at 37 °C. The cells were subsequently exposed to 100 g/m. The plates were incubated for 24 h, and cell proliferation was measured by adding 10 µL of MTT (thiazolyl blue tetrazolium bromide) dye (5 mg/ml in phosphate-buffered saline) per well. The plates were incubated for a further 4 h at 37 °C in a humidified chamber containing 5% Co2 Formazan crystals formed due to reduction of dye by viable cells in each well were dissolved in 200 µl DMSO, and absorbance was read at 490 nm.

Finally, the percentage cytotoxicity of the compounds was calculated by using following formula.

Since the absorbance was directly correlated with the number of viable cells, the percent viability was calculated from the absorbance. The IC50, the concentration of the drug at which 50% cell growth is inhibited, was calculated by the curve fitting of the cell viability data using Prism software.