Keratinocyte Cytotoxicity of Peracetic Acid Used as Sterilizing Agent for Implant Scaffolds.

Peracetic acid (PAA) has been used to sterilize biomaterial scaffolds and allografts before their implantation. Although the antimicrobial effectiveness of PAA is widely known, there are no studies investigating its cytotoxicity on keratinocytes. This study aimed to investigate the cytotoxicity of PAA concentrations on keratinocytes by growing HaCaT cells in culture medium. Different concentrations of PAA (control-untreated, 0.01, 0.1, 1, 10, 100, 200, 400, 800, 1200, 1600, and 2000 ppm) were added to the culture wells and allowed to be in direct contact with cells for up to 24 hours. Cytotoxicity was quantitatively and qualitatively determined by cell viability assay and analysis of morphological changes. Statistical analysis was performed with 1-way analysis of variance and Tukey test at 5% significance. Cells treated with 0.01 and 0.1 ppm followed the same morphological pattern of untreated cells, whereas cells treated with 1.0 ppm presented about 20% of floating cells and dark cytoplasmic granules. More than 50% of the cells treated with 10 and 100 ppm were destroyed, whereas the attached ones showed unclear and interrupted cell membranes. Concentrations of 1 ppm or greater had less than 64.4% of viable cells compared with the control group. This study concluded that exposure of keratinocytes to concentrations of 1 ppm or greater of PAA resulted in strong cytotoxic effects.