Researchers have developed a new tool and technique that uses “vortex ultrasound” – a sort of ultrasonic tornado – to break down blood clots in the brain. The new approach worked more quickly than existing techniques to eliminate clots formed in an in vitro model of cerebral venous sinus thrombosis (CVST).

“Our previous work looked at various techniques that use ultrasound to eliminate blood clots using what are essentially forward-facing waves,” says Xiaoning Jiang, co-corresponding author of a paper on the work. “Our new work uses vortex ultrasound, where the ultrasound waves have a helical wavefront. “In other words, the ultrasound is swirling as it moves forward,” says Jiang, who is the Dean F. Duncan Professor of Mechanical and Aerospace Engineering at North Carolina State University. “Based on our in vitro testing, this approach eliminates blood clots more quickly than existing techniques, largely because of the shear stress induced by the vortex wave.”

“The fact that our new technique works quickly is important, because CVST clots increase pressure on blood vessels in the brain,” says Chengzhi Shi, co-corresponding author of the work and an assistant professor of mechanical engineering at Georgia Tech. “This increases the risk of a hemorrhage in the brain, which can be catastrophic for patients. “Existing techniques rely in large part on interventions that dissolve the blood clot. But this is a time-consuming process. Our approach has the potential to address these clots more quickly, reducing risk for patients.”

CVST occurs when a blood clot forms in the veins responsible for draining blood from the brain. Incidence rates of CVST were between 2 and 3 per 100,000 in the United States in 2018 and 2019, and the incidence rate appears to be increasing.

“Another reason our work here is important is that current treatments for CVST fail in 20-40% of cases,” Jiang says.

Source: https://news.ncsu.edu/

Tiny silica bottles filled with medicine and a special temperature-sensitive material could be used for drug delivery to kill malignant cells only in certain parts of the body, according to a study published recently by researchers at the Georgia Institute of Technology. The research team devised a way to create silica-based hollow spheres around 200 nanometers in size, each with one small hole in the surface that could enable the spheres to encapsulate a wide range of payloads to be released later at certain temperatures only.

In the study, which was published on June 4 in the journal Angewandte Chemie International Edition, the researchers describe packing the spheres with a mixture of fatty acids, a near-infrared dye, and an anticancer drug. The fatty acids remain solid at human body temperature but melt a few degrees above. When an infrared laser is absorbed by the dye, the fatty acids will be quickly melted to release the therapeutic drug.

“This new method could allow infusion therapies to target specific parts of the body and potentially negating certain side effects because the medicine is released only where there’s an elevated temperature,” said Younan Xia, professor and Brock Family Chair in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University. “The rest of the drug remains encapsulated by the solid fatty acids inside the bottles, which are biocompatible and biodegradable.”

The researchers also showed that the size of the hole could be changed, enabling nanocapsules that release their payloads at different rates. “This approach holds great promise for medical applications that require drugs to be released in a controlled fashion and has advantages over other methods of controlled drug release,” Xia said.

Source: http://www.rh.gatech.edu/

From liquid laundry detergent packaged in cardboard to compostable plastic cups, consumer products these days are increasingly touting their sustainable and renewable origins. Now researchers at Georgia Institute of Technology have created a material derived from crab shells and tree fibers that has the potential to replace the flexible plastic packaging used to keep food fresh. The new material, which is described in the journal ACS Sustainable Chemistry and Engineering, is made by spraying multiple layers of chitin from crab shells and cellulose from trees to form a flexible film similar to plastic packaging film.

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“The main benchmark that we compare it to is PET, or polyethylene terephthalate, one of the most common petroleum-based materials in the transparent packaging you see in vending machines and soft drink bottles,” said J. Carson Meredith, a professor in Georgia Tech’s School of Chemical and Biomolecular Engineering. “Our material showed up to a 67 percent reduction in oxygen permeability over some forms of PET, which means it could in theory keep foods fresher longer.”

Cellulose, which comes from plants, is the planet’s most common natural biopolymer, followed next by chitin, which is found in shellfish, insects and fungi.

Source: http://www.news.gatech.edu/