RT Journal Article SR Electronic T1 Magneto-acoustic protein nanostructures for non-invasive imaging of tissue mechanics in vivo JF bioRxiv FD Cold Spring Harbor Laboratory SP 2022.05.26.493158 DO 10.1101/2022.05.26.493158 A1 Whee-Soo Kim A1 Sungjin Min A1 Su Kyeom Kim A1 Sunghwi Kang A1 Hunter Davis A1 Avinoam Bar-Zion A1 Dina Malounda A1 Yu Heun Kim A1 Soohwan An A1 Jae-Hyun Lee A1 Soo Han Bae A1 Jin Gu Lee A1 Minsuk Kwak A1 Seung-Woo Cho A1 Mikhail G. Shapiro A1 Jinwoo Cheon YR 2022 UL http://biorxiv.org/content/early/2022/05/27/2022.05.26.493158.abstract AB Measuring cellular and tissue mechanics inside intact living organisms is essential for interrogating the roles of force in physiological and disease processes, and is a major goal in the field of mechanobiology. However, existing biosensors for 3D tissue mechanics, primarily based on fluorescent emissions and deformable materials, are limited for in vivo measurement due to the limited light penetration and poor material stability inside intact, living organisms. While magneto-motive ultrasound (MMUS), which uses superparamagnetic nanoparticles as imaging contrast agents, has emerged as a promising modality for real-time in vivo imaging of tissue mechanics, it has poor sensitivity and spatiotemporal resolution. To overcome these limitations, we introduce magneto-gas vesicles (MGVs), a unique class of protein nanostructures based on gas vesicles and magnetic nanoparticles that produces differential ultrasound signals in response to varying mechanical properties of surrounding tissues. These hybrid protein nanostructures significantly improve signal strength and detection sensitivity. Furthermore, MGVs enable non-invasive, long-term, and quantitative measurement of mechanical properties within 3D tissues and organs in vivo. We demonstrated the performance of MGV-based mechano-sensors in vitro, in fibrosis models of organoids, and in vivo in mouse liver fibrosis models.Competing Interest StatementThe authors have declared no competing interest.