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

Abstract

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.

Purification of living environments using photocatalysts: Inactivation of microorganisms and decomposition of allergens

“…Photocatalysts have strong oxidation-reduction abilities and can decompose organic matter; therefore, they have attracted attention as antibacterial and antiviral materials [ 19 ]. Photocatalysts are expected to decompose allergens [ 47 ].…”

“…Sterilization is primarily caused by damage to the bacterial cell membranes [ 1 , 12 , 25 , 46 , 91 ]. Although detailed research is limited, allergens can be degraded [ 47 , 64 , 73 , 74 , 85 ]. Photocatalysts are installed in air conditioners and air purifiers, and are used to preserve food in refrigerators and fabricate antiviral and antibacterial walls and floors [ 26 ].…”

“…Photocatalysts can decompose high-molecular-weight organic substances such as viral proteins and endotoxins, and are therefore expected to be effective in removing allergens. However, only a few studies have been conducted on the decomposition of allergens using photocatalysts compared to the inactivation of viruses and elimination of bacteria [ 47 , 73 , 74 , 75 , 85 ] ( Table 3…”

“…In 2023, Matsuura et al . first reported the photocatalytic decomposition of cat and dog allergens, which are essential allergens in living environments, and the reduction of dog allergens [ 47 ] ( Fig. 6A

Fig.

…”