Genetic Modulation of Biosynthetic Gas Vesicles for Ultrasound Imaging.

Gas vesicles (GVs) from microorganisms are genetically air-filled protein nanostructures, and serve as a new class of nanoscale contrast agents for ultrasound imaging. Recently, the genetically encoded GV gene clusters have been heterologously expressed in Escherichia coli, allowing these genetically engineered bacteria to be visualized in vivo in a real-time manner by ultrasound. However, most of the GV genes remained functionally uncharacterized, which makes it difficult to regulate and modify GVs for broad medical applications.

Modification of PEG reduces the immunogenicity of biosynthetic gas vesicles.

Nanobubbles have received great attention in ultrasound molecular imaging due to their capability to pass through the vasculature and reach extravascular tissues. Recently, gas vesicles (GVs) from archaea have been reported as acoustic contrast agents, showing great potential for ultrasound molecular imaging. However, the immunogenicity and biosafety of GVs has not yet been investigated.

Biosynthesis of Melanin Nanoparticles for Photoacoustic Imaging Guided Photothermal Therapy.

Photothermal therapy (PTT) has attracted considerable attention in recent years due to their unique advantages in minimal invasiveness and spatiotemporal selectivity. However, the fabrication procedures of PTT agents frequently require complex chemical and/or physical methods that involves harsh and environmentally hazardous conditions. Here, a genetically engineered bacterium is developed to synthesize melanin nanoparticles under mild and environmentally friendly conditions.