Cytotoxicity testing of wound-dressing materials

By Sahlin, H. - Nygren, H.

A method was developed for testing the cytotoxicity of various bandage-like wound dressings and gel wound dressings. In this method, the ability of human polymorphonuclear neutrophils (PMNs) to initiate a respiratory burst after exposure to the various wound dressings is used as a marker of cytotoxicity. Luminol-amplified chemiluminescence stimulated with opsonised zymosan or phorbol 12-myristate 13-acetate (PMA) is used to measure the degree of activation of the respiratory burst, i.e. the NADPH oxidase activity, after exposure to wound dressings. Opsonised zymosan (material from yeast cell walls) is a phagocytic stimulus that activates the NADPH oxidase by binding to Fc-receptors and complement receptors, and functions as an artificial bacterium, whereas PMA activates the NADPH oxidase by direct activation of protein kinase C. NADPH oxidase activity was inhibited by several wound dressings. The down-regulation of the respiratory burst is detrimental to the bactericidal effect of PMNs, and can be used as a marker for the cytotoxicity of wound-dressing materials.