Until now, researchers have been unable to accurately study the
flexibility of microbubble shells, which are injected into the
bloodstream as an aid to ultrasound imaging.
This lack of information meant that it was hard to predict
exactly how the bubbles would behave under the ultrasound
beams.
By adding a glowing molecule just beneath the outer shell of the
bubble, researchers at Imperial College London and the University
of Oxford were able to study the shells of bubbles in minute detail
for the first time using a powerful microscope.
This allowed them to accurately map microbubble shells and
determine how flexible they are and could lead to future
applications for targeting drug delivery to specific areas that
require treatment.
One of the lead researchers, Dr Marina Kuimova, from the
Department of Chemistry at Imperial, said: "The new technique can
potentially have a big impact on our understanding of how
microbubbles interact with living cells and each other in blood
vessels. We can now begin work on how to manipulate or
manufacture microbubbles for use in medical treatments."
The researchers demonstrated that addition of the certain
molecules to the bubble shells makes them more stable. In the
future, scientists could replace these molecules with drugs, so
that the bubbles could deliver medicine in an efficient, targeted
way.
Information about the properties and behaviours of microbubbles
may also be used to improve how they are created so that bubbles
can be designed for specific biomedical purposes, such as enhancing
how they are used in ultrasound and for delivering drugs directly
to where they are required in the body.
Dr Eleanor Stride, from the University of Oxford, added: "This
valuable new method will enable us to understand how the
microbubble manufacturing techniques we are developing affect the
properties of the microbubbles and hence how we can optimise their
response to ultrasound for both imaging and drug delivery
applications."
The paper, Mapping microbubble viscosity using fluorescence lifetime imaging
of molecular rotors, is published in the Proceedings of theNational Academy of Sciences.