TiO2-Photocatalyst-Induced Degradation of Dog and Cat Allergens under Wet and Dry Conditions Causes a Loss in Their Allergenicity

Allergies to dogs and cats can cause enormous damage to human health and the economy. Dog and cat allergens are mainly found in dog and cat dander and are present in small particles in the air and in carpets in homes with dogs and cats. Cleaning houses and washing pets are the main methods for reducing allergens in homes; however, it is difficult to eliminate them completely. Therefore, we aimed to investigate whether a TiO₂ photocatalyst could degrade dog and cat allergens. Under wet conditions, exposure to the TiO₂ photocatalyst for 24 h degraded Can f1, which is a major dog allergen extracted from dog dander, by 98.3%, and Fel d1, which is a major cat allergen extracted from cat dander, by 93.6-94.4%. Furthermore, under dry conditions, the TiO₂ photocatalyst degraded Can f1 and Fel d1 by 92.8% and 59.2-68.4%, respectively. The TiO₂ photocatalyst abolished the binding of dog and cat allergens to human IgE by 104.6% and 108.6%, respectively. The results indicated that the TiO₂ photocatalyst degraded dog and cat allergens, causing a loss in their allergenicity. Our results suggest that TiO₂ photocatalysis can be useful for removing indoor pet allergens and improving the partnership between humans and pets.