Sonication-Assisted Self-Assembled Resveratrol Nanoparticles with Enhanced Antiviral and Anti-inflammatory Activity against Respiratory Syncytial Virus-Induced Pneumonia

Respiratory syncytial virus (RSV)-induced viral pneumonia in children is common worldwide. Its high occurrence and lack of an effective vaccine make it a leading cause of death in children. Severe RSV infection can trigger uncontrolled inflammatory responses in patients, so the development of small molecule drugs with the dual function of "direct antivirus" and "inflammatory response regulation" is welcome. Resveratrol (Res) has been reported to have antiviral and anti-inflammatory pharmacological effects, but its application is limited because of its poor water solubility and oral bioavailability. Based on small-molecule nanotechnology, we developed a sonication-assisted self-assembly method for preparing insoluble Res into highly soluble resveratrol nanoparticles (Res NPs). The obtained Res NPs exhibited a higher water solubility and a faster dissolution rate, which was more conducive to the effectiveness of Res in addressing RSV-induced viral pneumonia. In vitro studies had shown that Res NPs played an antiviral role by inhibiting RSV replication and reducing the production of pro-inflammatory cytokines. Nebulized inhalation administration of Res NPs prolonged the drug's residence time in the lungs, which appears to increase the accumulation and effectiveness of Res NPs. Additionally, in vivo studies had demonstrated significant benefits of Res NPs in inhibiting RSV viral load and improving the pulmonary microenvironment in RSV-infected mice. Both antiviral and anti-inflammatory experiments had confirmed that the pharmacological activity of Res NPs is superior to that of Res. This suggested that nanosizing Res was an effective way to enhance the original pharmacological activity of Res and also offered a new formulation strategy for treating viral pneumonia.