ABSTRACT
Advanced mRNA vaccines play vital roles against SARS-CoV-2. However, due to the poor stability, most current mRNA delivery platforms need to be stored at -20 {degrees}C or -70 {degrees}C. Here we present lyophilized thermostable mRNA loaded lipid nanoparticles, which could be stored at room temperature with long-term stability. We demonstrate the applicability of lyophilization techniques to different mRNA sequences and lipid components. Three lyophilized vaccines targeting wild-type, Delta and Omicron SARS-CoV-2 variant were prepared and demonstrated to be able induce high-level of IgG titer and neutralization response. In the Delta challenge in vivo experiment, the lyophilized mRNA vaccine successfully protected the mice from infection and clear the virus. This lyophilization platform could significantly improve the accessibility of mRNA vaccine or therapeutics, particularly in remote regions.
ABSTRACT
Human exposure risks to airborne pollutants, bacteria and viruses in confined spaces have attracted tremendous attention. It is a challenge to degrade these harmful materials over a single device by electrical method other than conventional thermal method. We fabricated an air cleaning device based on a conductive Ag-Co3O4 coating with Ag nanoparticles on a glass fibre cloth (GFC). The device possessed good flexibility and high permeability of the GFC. Powered by low-voltages (< 20 V), the device exhibited a 3-fold formaldehyde conversion in its conventional thermal counterpart, and energy savings of > 90% were achieved. The electrically treated device completely killed Escherichia coli and Staphylococcus aureus and SARS-CoV-2 pseudovirus within a few minutes at a low surface temperature of < 50 °C. The excellent efficiency of the devices was attributed to the confinement of electric power to the coating. The device can serve as a flexible filter for air cleaners or conditioners to ensure that human health is maintained amid the pandemic.