Microbubbles have been the earliest and most widely used ultrasound contrast agents by virtue of their unique features:such as non-toxicity,intravenous inject-ability,ability to cross the pulmonary capillary bed,and s...Microbubbles have been the earliest and most widely used ultrasound contrast agents by virtue of their unique features:such as non-toxicity,intravenous inject-ability,ability to cross the pulmonary capillary bed,and significant enhancement of echo signals for the duration of the examination,resulting in essential preclinical and clinical applications.The use of microbubbles functional-ized with targeting ligands to bind to specific targets in the bloodstream has further enabled ultrasound molecular imaging.Nevertheless,it is very challenging to utilize targeted microbubbles for molecular imaging of extra-vascular targets due to their size.A series of acoustic nanomaterials have been developed for breaking free from this constraint.Especially,biogenic gas vesicles,gas-filled protein nanostructures from microorganisms,were engineered as thefirst biomolecular ultrasound contrast agents,opening the door for more direct visual-ization of cellular and molecular function by ultrasound imaging.The ordered protein shell structure and unique gasfilling mechanism of biogenic gas vesicles endow them with excellent stability and attractive acoustic responses.What’s more,their genetic encodability enables them to act as acoustic reporter genes.This article reviews the upgrading progresses of ultrasound contrast agents from microbubbles to biogenic gas vesicles,and the opportu-nities and challenges for the commercial and clinical translation of the nascentfield of biomolecular ultrasound.展开更多
基金financially supported by National Project for Research and Development of Major Scientific Instruments(No.81727803)National Natural Science Foundation of China(No.82071980),State Key Program of National Natural Science of China(No.81930047)Projects of International Cooperation and Exchanges NSFC-PSF(No.31961143003).
文摘Microbubbles have been the earliest and most widely used ultrasound contrast agents by virtue of their unique features:such as non-toxicity,intravenous inject-ability,ability to cross the pulmonary capillary bed,and significant enhancement of echo signals for the duration of the examination,resulting in essential preclinical and clinical applications.The use of microbubbles functional-ized with targeting ligands to bind to specific targets in the bloodstream has further enabled ultrasound molecular imaging.Nevertheless,it is very challenging to utilize targeted microbubbles for molecular imaging of extra-vascular targets due to their size.A series of acoustic nanomaterials have been developed for breaking free from this constraint.Especially,biogenic gas vesicles,gas-filled protein nanostructures from microorganisms,were engineered as thefirst biomolecular ultrasound contrast agents,opening the door for more direct visual-ization of cellular and molecular function by ultrasound imaging.The ordered protein shell structure and unique gasfilling mechanism of biogenic gas vesicles endow them with excellent stability and attractive acoustic responses.What’s more,their genetic encodability enables them to act as acoustic reporter genes.This article reviews the upgrading progresses of ultrasound contrast agents from microbubbles to biogenic gas vesicles,and the opportu-nities and challenges for the commercial and clinical translation of the nascentfield of biomolecular ultrasound.
