In the last three years how often have you wished there was cause to take a sigh of relief? Thanks to some BME researchers, the near future may bring a particularly effective sigh of relief. Ke Cheng, the Randall B. Terry Jr. Distinguished Professor in Regenerative Medicine at NC State and the UNC/NC State Joint Department of Biomedical Engineering, along with colleagues from UNC-Chapel Hill and Duke University, led the development of an inhalable COVID-19 vaccine that is shelf stable at room temperature for up to three months, targets the lungs specifically and effectively, and allows for self-administration via an inhaler. The researchers also found that the delivery mechanism for this vaccine is effective at evading the lung’s mucosal lining and can be used effectively with protein-based vaccines. In order to deliver the vaccine directly to the lungs, the researchers used exosomes (Exo) secreted from lung spheroid cells (LSCs). Exosomes are nanosized vesicles that have recently been recognized as an excellent means of drug delivery. Dr. Cheng’s team created and tested an inhalable, protein-based, virus-like particle (VLP) vaccine by decorating the exterior of LSC-Exo with a portion of the spike protein from the SARS-CoV-2 virus. In rodent models, the protein-decorated LSC-Exo vaccine elicited production of antibodies specific to the spike protein, and protected the rodents, after two vaccine doses, from infection with live SARS-CoV-2. Additionally, the inhalable vaccine remained stable at room temperature for three months. The researchers note that while the work is promising, there are still challenges associated with large-scale production and purification of the exosomes. LSCs are currently in a Phase I clinical trial by the same researchers for treating patients with degenerative lung diseases. Read more about Dr. Cheng’s exciting work in detailed stories at UNC or NC State. Links to the group’s recent journal publications on these topics can be found there.