Nanoformulations for Respiratory Infections

The members of the Coronavirus family including severe acute respiratory syndrome (SARS) coronavirus 1 (SARS-CoV1), MERS-CoV and SARS-CoV-2 (synonym: CoV2), have caused pandemics respectively in 2003, 2012 and 2019 suggesting the possibility of a future pandemic by this virus family. Also, following the COVID-19 pandemic, there was an increase in other seasonal respiratory infections such as influenza and respiratory syncytial virus (RSV). Severe respiratory viral infections can cause robust viral replication and a strong 'cytokine storm' leading to acute respiratory distress syndrome and pneumonia often leading to death in the case of elderly (>65 years of age). Currently, a limited number of moderately effective therapies are available, hence there is a dire need to develop additional novel therapeutics against respiratory infections. The main premise of this proposal is to develop a broad-spectrum antiviral intranasal nanoformulation using CoV2 and RSV as models. To this end, a liposomal nanosystem comprising alpha linolenic-acid (ALA) and acetate (acronym: LAN) has been established, wherein liposomes composed of ALA incorporate acetate in the lipid bilayer that can activate type-I IFN pathway and inhibit viral replication. Also, ALA binding to viral fusion proteins disrupts LANs releasing acetate. Based on this progress, herein it is proposed to incorporate in the core a slow-sustained release nanochitosan particle complexed with pDNA(s) encoding short-hairpin RNAs (pshRNA) for CoV2/RSV. Thus, a novel set of candidate shRNAs has been identified, which synergistically decreases CoV2 replication and overall infection. All data at hand taken together have led to the central hypothesis that the development of a LAN with virus-specific regimens such pshRNA(s) can act in an additive or synergistic manner to produce the most robust therapy against severe respiratory infections. This hypothesis will be tested in the following two aims. Aim #1 will test the hypothesis that incorporating pshRNA to the LAN core (pshLAN) can make a more potent antiviral, and to this end, it is proposed to synthesize and characterize pshLAN, test for synergy in vitro in lung epithelial cell and air-liquid organoid cultures, and test biodistribution and toxicity of LAN/pshLAN in vivo. In Aim #2, to test whether LANs with pshRNAs endow synergistic therapeutic efficacy in vivo, it is planned to compare the efficacy of pshLAN vs LAN using aged mouse models of viral infections by CoV2-MA10 or clinical RSV isolates and examine the mechanism of efficacy and synergy in vivo. All required resources and facilities including access to Nanomedicine Core and the BSL3/ABSL3 facilities for CoV2 research are in place. The investigative team is uniquely poised to test whether the proposed core-shell LAN-based nanomedicine can effectively treat CoV2 and/or RSV infections, which can be extended to other infections in the future.