title: Molecular Engineering of Acoustic Protein Nanostructures.
abstract: Ultrasound is among the most widely used biomedical imaging modalities, but has limited ability to image specific molecular targets due to the lack of suitable nanoscale contrast agents. Gas vesicles-genetically encoded protein nanostructures isolated from buoyant photosynthetic microbes-have recently been identified as nanoscale reporters for ultrasound. Their unique physical properties give gas vesicles significant advantages over conventional microbubble contrast agents, including nanoscale dimensions and inherent physical stability. Furthermore, as a genetically encoded material, gas vesicles present the possibility that the nanoscale mechanical, acoustic, and targeting properties of an imaging agent can be engineered at the level of its constituent proteins. Here, we demonstrate that genetic engineering of gas vesicles results in nanostructures with new mechanical, acoustic, surface, and functional properties to enable harmonic, multiplexed, and multimodal ultrasound imaging as well as cell-specific molecular targeting. These results establish a biomolecular platform for the engineering of acoustic nanomaterials.
authors.affiliation: Division of Biology and Biological Engineering, ‡Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena, California-91125, United States.
authors.forename: Anupama
authors.initials: A
authors.lastname: Lakshmanan
authors.affiliation: Division of Biology and Biological Engineering, ‡Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena, California-91125, United States.
authors.forename: Arash
authors.initials: A
authors.lastname: Farhadi
authors.affiliation: Division of Biology and Biological Engineering, ‡Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena, California-91125, United States.
authors.forename: Suchita P
authors.initials: SP
authors.lastname: Nety
authors.affiliation: Division of Biology and Biological Engineering, ‡Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena, California-91125, United States.
authors.forename: Audrey
authors.initials: A
authors.lastname: Lee-Gosselin
authors.affiliation: Division of Biology and Biological Engineering, ‡Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena, California-91125, United States.
authors.forename: Raymond W
authors.initials: RW
authors.lastname: Bourdeau
authors.affiliation: Division of Biology and Biological Engineering, ‡Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena, California-91125, United States.
authors.forename: David
authors.initials: D
authors.lastname: Maresca
authors.affiliation: Division of Biology and Biological Engineering, ‡Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena, California-91125, United States.
authors.forename: Mikhail G
authors.initials: MG
authors.lastname: Shapiro
mesh_terms: D000162:Acoustics; D003287:Contrast Media; D045423:Microbubbles; D049329:Nanostructures; D011506:Proteins / Q000737:chemistry*; D014463:Ultrasonography
chemical_list: D003287:Contrast Media; D011506:Proteins
keywords: acoustic nanostructures; cancer; contrast agents; gas vesicles; genetic engineering; macrophages; molecular imaging; protein engineering; ultrasound