Pre-Treatment with Zirconia Nanoparticles Reduces Inflammation Induced by the Pathogenic H5N1 Influenza Virus

Huo, Caiyun; Xiao, Jin; Xiao, Kai; Zou, Shumei; Wang, Ming; Qi, Peng; Liu, Tianlong; Hu, Yanxin

In recent decades, nanoparticles (NPs) have increasingly been applied as an inexpensive and easy-to-use detection method as well as a promising adjuvant against viral infections due to their unique physical and chemical characteristics and strong activation of the immune system. Due to these structural and chemical properties, nanomaterials have several advantages over bulk materials of the same composition, including small size, high surface area-to-volume ratio, and ease of preparation and modification. NPs can affect immune responses by binding to serum proteins. In previous studies, NPs have shown specific immunomodulatory effects on immune cells, as well as antiviral, antioxidant, and anticancer capabilities. [19] [20] [21] In particular, virus-like particles (alundum and mesoporous silica) have received great attention for potential application as adjuvants. [22] [23] [24] However, because protein or DNA vaccines exhibit poor stability in vivo, most reported NPs have been used only as efficient antigen delivery systems. Although NPs can enhance immunity, few studies to date have focused on the antiviral function of NPs rather than using them only as protein or DNA carriers. 25 The nanomaterial-activated immune response must be overcome when NPs are used as carriers. [26] [27] [28] To date, little attention has been paid to the antiviral effects of NPs without virus-based antigens. Nanoparticles of ZrO 2 , a nano-sized and hollow colloidal metal oxide with controllable thickness, were synthesized using a robust sol-gel process and show superior catalytic activity for many reactions due to the unique physicochemical characteristics of the surface of ZrO 2 . 29,30 ZrO 2 has been widely used as a catalyst in many engineering applications and offers an environmentally-friendly option for chemical and pharmaceutical industries. 30 It is also used as an anticancer agent in the treatment of colon cancer. 31 Despite their potential biomedical applications, few studies have reported on the use of ZrO 2 as an antiviral material.