Table 1.

Comparison of the cell survival rates (% of optical density of the extract treated cells) to the control group of the treated materials in different incubation periods.

Incubation period	Nanoparticles concentration (μg/ml)	Mean MTT cell viability	Std. deviation	Cell survival rate (%)
Day 1–24✝	0	0.49	0.03	81
	0.5	0.48	0.04	80
	5	0.44	0.01	73
	50	0.42	0.01	70
	500	0.39	0.04	65*
Day1–72✝	0	0.42	0.01	79
	0.5	0.41	0.01	75
	5	0.39	0.01	73
	50	0.32	0.01	60*
	500	0.28	0.01	52*
Day3–24	0	0.55	0.05	84
	0.5	0.53	0.05	81
	5	0.49	0.03	75
	50	0.42	0.01	70
	500	0.44	0.02	67*
Day3–72	0	0.44	0.03	81
	0.5	0.41	0.02	77
	5	0.40	0.01	74
	50	0.35	0.02	64*
	500	0.31	0.01	57*
Day5–24	0	0.71	0.06	92
	0.5	0.64	0.07	83
	5	0.60	0.03	77
	50	0.59	0.04	76
	500	0.53	0.01	68*
Day5–72	0	0.45	0.02	81
	0.5	0.43	0.01	78
	5	0.41	0.02	74
	50	0.39	0.02	70
	500	0.33	0.01	60*
Day7–24	0	0.85	0.03	97
	0.5	0.79	0.04	90
	5	0.71	0.03	81
	50	0.69	0.02	79
	500	0.61	0.04	70
Day7–72	0	0.48	0.03	82
	0.5	0.46	0.04	79
	5	0.43	0.01	74
	50	0.42	0.01	72
	500	0.41	0.03	70

*Concentrations at which copper oxide nanoparticles are considered cytotoxic.

^✝The cell viability was tested after 24 h and 72 h of contact with HGF cells after each incubation period (days 1, 3, 5, and 7).