An in vitro method to predict acute lung toxicity due to pulmonary surfactant inhibition

Jorid Birkelund Sørli, Søren Thor Larsen

Spray products for impregnation, such as those used for shoes, textiles, and building materials, are widespread in both private households and industry. These products are intended to form a water- and dirt-repellent film on the surface of materials, thereby providing protection.

During application, small liquid droplets (aerosols) are released into the air, which can be inhaled. Unfortunately, a small proportion of marketed products have been shown to cause acute poisoning in users and others nearby during the spraying process. Symptoms typically include coughing and shortness of breath, but in more severe cases can also involve reduced lung function and partial lung collapse.

The current standard method for assessing acute lung toxicity of spray products involves exposing mice or rats to aerosols of the product and measuring their respiratory function.

We have demonstrated that the toxicity of impregnation sprays may be due to their ability to damage pulmonary surfactant, a thin liquid film lining the inside of the lungs. Pulmonary surfactant ensures that the lungs do not collapse during breathing, and the fact that certain impregnation sprays can impair the function of the surfactant helps explain why partial lung collapse is observed in cases of severe poisoning with these products.

By testing the effects of various spray products on pulmonary surfactant isolated from slaughter pigs, we have shown that products causing acute lung toxicity in mice also impair surfactant function in an in vitro setup. Unfortunately, the current in vitro method only works for water-soluble products. As a result, it has not been possible to test the many oil-soluble products available on the market.

The aim of the new project is to further develop the in vitro method so that a broader range of impregnation spray products, including oil-soluble ones, can be tested. If the method proves effective, it can be used to screen new spray products for acute lung toxicity, thereby reducing the number of laboratory animals needed for this purpose.

• Prediction of Acute Inhalation Toxicity Using in vitro Lung Surfactant Inhibition (Altex)

Sign up for our newsletter - don't miss information about our annual symposium etc.