To investigate the effect of human serum on corneal epithelial cells.

Changes of corneal epithelial cells were evaluated after 1, 4, 12, and 24 hours (hrs) of exposure to various concentrations of human serum (3, 5, 8, and 16%). Cellular metabolic activity and the extent of cellular damage were measured. Effect of human serum on cell migration was also examined. Concentration of procollagen type-I COOH-terminal peptide (PIP), epidermal growth factor (EGF), and laminin after exposure to human serum was further observed.

In every concentration of human serum, metabolic activity of the corneal epithelial cells temporarily decreased at 4 hrs of exposure and recovered to baseline levels afterward. With the same exposure time, there was no statistically significant difference in metabolic activity between the human serum-exposed group and the control group. Cellular toxicity of human serum exhibited a time- and dose-dependent relationship. Cellular migration was observed after 24 hrs of exposure to 5% concentration of human serum and after 12 hrs of exposure to 8% and 16% concentration of human serum. The PIP, EGF, and laminin titers increased in time- and dose-dependent manners.

Human serum does not decrease the metabolic activity of corneal epithelial cells as the concentration and exposure time increase, but it can induce cytotoxicity. Considering cellular migration, a serum concentration of 5% or higher should be used.