A Novel Catalase Nanogels for Effective Treatment of Neutrophilic Asthma.

Neutrophilic asthma, as corticosteroid resistant asthma, is clinically more severe than eosinophilic asthma. Therefore, the treatment of neutrophilic asthma has been a challenging. Reactive oxygen species (ROS) play a key role in the neutrophilic asthma. However, the direct use of antioxidant enzymes, such as catalase (CAT), is challenging due to the poor stability, short plasma half‐life, and the lack of effective drug delivery systems to pulmonary systems. In this work, a novel kind of nanogels for delivering CAT (CAT‐NGs) is synthesized, incorporating CAT with an antibacterial "protective film", as a modality for the treatment of neutrophilic asthma. Compared with free CAT, CAT‐NGs demonstrated superior enzyme activity and trypsin resistance, and exhibited outstanding anti‐inflammatory and antioxidant activities in vitro. Furthermore, CAT‐NGs showed significant inhibitory effects on nontypeable Haemophilus influenzae (NTHi), Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Additionally, nebulized inhalation of CAT‐NGs alleviated pulmonary inflammation in neutrophilic asthma mice. Mechanistically, the alleviation of neutrophilic asthma symptoms by CAT‐NGs is possibly associated with the clearance of ROS in the lung and the inhibition of the NLRP3 and NF‐κB pathways. Hence, the work have demonstrated the therapeutic potential of CAT‐NGs, offering new insights into the clinical treatment of neutrophilic asthma. [ABSTRACT FROM AUTHOR]