Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study Finds Plasmin—Delivered Through A Bubble—More Effective Than Tpa In Busting Clots

16.05.2013
A new study from the University of Cincinnati (UC) College of Medicine has found that, when delivered via ultrasound, the natural enzyme plasmin is more effective at dissolving stroke-causing clots than the standard of care, recombinant tissue plasminogen activator (rt-PA).

The novel delivery method involved trapping plasmin into bubble-like liposomes, delivering them to the clot intravenously and bursting it via ultrasound. That method is necessary, says UC associate professor of emergency medicine George "Chip” Shaw III, MD, PhD, because plasmin cannot be delivered through traditional methods. Intravenous delivery of rt-PA is designed to solve that problem by catalyzing the conversion of existing plasminogen inside the body to plasmin, which in turn degrades blood clots.

"Plasmin is the enzyme that actually chews up the fibrin in clots,” says Shaw. "The problem is you can only give plasmin inter-arterially, which has safety risks and takes longer to deliver. IV therapy is always easier and quicker, but if you give plasmin intravenously, the body inhibits it immediately. If you can encapsulate it, it doesn’t get inhibited and you can target it to the clot.”

In their in-vitro study, Shaw and researchers Madhuvathi Kandadai, PhD, and Jason Meunier, PhD, enclosed plasmin and a gas bubble inside a liposome. They then delivered the liposome to a clot in an in-vitro lab clot model and dissolved it using ultrasound waves, thus delivering the plasmin enzyme to the clot. After 30 minutes, clots treated with plasmin showed significantly greater breakdown than clots treated with rt-PA.

They worked with colleague Christy Holland, PhD, professor in UC’s cardiovascular diseases division, to develop the technique. As director of the Image-guided Ultrasound Therapeutics Laboratories at UC, Holland has studied the use of liposomes and ultrasound to deliver drugs in a less invasive, more targeted fashion.

The standard of care for acute ischemic stroke is intravenous delivery of U.S. Food and Drug Administration-approved rt-PA within three hours of stroke onset. Ischemic stroke is the most common type of stroke, accounting for about 87 percent of all stroke cases.

But Shaw says there is a "critical need” for a safer and more effective thrombolytic, as rt-PA carries a risk of bleeding. Intracranial hemorrhage currently occurs in 6 percent of patients receiving rt-PA therapy.

"Previous in vivo studies have demonstrated better safety of plasmin as compared with rt-PA,” he says. "Currently, intra-arterial plasmin is undergoing clinical trials. Our next step is to work on targeting the liposome by putting antibodies on its surface that will stick it to the clot. We also want to improve the efficiency of encapsulating the plasmin in the liposome. Right now, about 15 percent of the plasmin gets into the liposome—we’re aiming for 50 percent.”

Kandadai, a postdoctoral fellow in the UC Department of Emergency Medicine, will present the abstract, "Plasmin loaded echogenic liposomes: A Novel Thrombolytic,” at the Society for Academic Emergency Medicine annual meeting May 14-18 in Atlanta. Meunier, a research assistant professor of emergency medicine, is also a co-author.

Katy Cosse | EurekAlert!
Further information:
http://www.healthnews.uc.edu/

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First diode for magnetic fields

Innsbruck quantum physicists have constructed a diode for magnetic fields and then tested it in the laboratory. The device, developed by the research groups led by the theorist Oriol Romero-Isart and the experimental physicist Gerhard Kirchmair, could open up a number of new applications.

Electric diodes are essential electronic components that conduct electricity in one direction but prevent conduction in the opposite one. They are found at the...

Im Focus: Nonstop Tranport of Cargo in Nanomachines

Max Planck researchers revel the nano-structure of molecular trains and the reason for smooth transport in cellular antennas.

Moving around, sensing the extracellular environment, and signaling to other cells are important for a cell to function properly. Responsible for those tasks...

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Optical Coherence Tomography: German-Japanese Research Alliance hosted Medical Imaging Conference

19.11.2018 | Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

 
Latest News

Helping to Transport Proteins Inside the Cell

21.11.2018 | Life Sciences

Meta-surface corrects for chromatic aberrations across all kinds of lenses

21.11.2018 | Power and Electrical Engineering

Removing toxic mercury from contaminated water

21.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>