Agradecimentos: Authors thank Lisa Bachman and Robert Estey for preparation of chewing gums, Admiral Instruments for donating the potentiostats used in the electrochemical experiments for RAPID assays and Naila Shahid for quantification of proteins in lablab bean powder. Authors thank Steven Szewczyk and Michelle Paolicelli for assisting with chewing gum protein release studies and acknowledge use of facilities and instrumentation supported by the Materials Science and Engineering Departmental Laboratory at the University of Pennsylvania and NSF through the University of Pennsylvania Materials Research Science and Engineering Center (MRSEC) (DMR-1720530). Research in the Daniell laboratory is supported by funding from NIH grant R01 HL 107904, R01 HL 109442, R01 HL 133191. Commonwealth of Pennsylvania, Department of Community and Economic Development grant to HD on "COVID-19 Pennsylvania Discoveries: Responding to SARS-COV-2 Through Innovation Commercialization" funded purchase of freeze dryers, toxicology studies on ACE2 produced at Fraunhofer USA/AeroFarms and production of the chewing gum. NP/OP sample collection in the Collman lab is supported by R33-HL137063 and the Penn Center for Coronavirus Research. Microbubbling assay in the Wang laboratory is supported by funding from the Penn Center for Precision Medicine, Penn Health-Tech, Penn Center for Innovation and Precision Dentistry, NIH RADx and BARDA. RAPID assay is supported by the Nemirovsky Prize and the Dean's Innovation Fund from the Perelman School of Medicine at the University of Pennsylvania. Research in Ma laboratory is supported by Taiwan Ministry of Science and Technology (MOST 110-2113-M-001-034-MY3) Ver menos

Abstract: Because oral transmission of SARS-CoV-2 is 3-5 orders of magnitude higher than nasal transmission, we investigated debulking of oral viruses using viral trap proteins (CTB-ACE2, FRIL) expressed in plant cells, delivered through the chewing gum. In omicron nasopharyngeal (NP) samples, the microbubble count (based on N-antigen) was significantly reduced by 20 µg of FRIL (p < 0.0001) and 0.925 µg of CTB-ACE2 (p = 0.0001). Among 20 delta or omicron NP samples, 17 had virus load reduced below the detection level of spike protein in the RAPID assay, after incubation with the CTB-ACE2 gum powder. A dose-dependent 50% plaque reduction with 50-100 ng FRIL or 600-800 µg FRIL gum against Influenza strains H1N1, H3N2, and Coronavirus HCoV-OC43 was observed with both purified FRIL, lablab bean powder or gum. In electron micrographs, large/densely packed clumps of overlapping influenza particles and FRIL protein were observed. Chewing simulator studies revealed that CTB-ACE2 release was time/dose-dependent and release was linear up to 20 min chewing. Phase I/II placebo-controlled, double-blinded clinical trial (IND 154897) is in progress to evaluate viral load in saliva before or after chewing CTB-ACE2/placebo gum. Collectively, this study advances the concept of chewing gum to deliver proteins to debulk oral viruses and decrease infection/transmission Ver menos