Nav: Home

'Waltzing' nanoparticles could advance search for better drug delivery methods

November 13, 2018

BLOOMINGTON, Ind. -- Indiana University researchers have discovered that drug-delivering nanoparticles attach to their targets differently based upon their position when they meet -- like ballroom dancers who change their moves with the music.

The study, published Nov. 13 in the journal ACS Nano, is significant since the "movement" of therapeutic particles when they bind to receptor sites on human cells could indicate the effectiveness of drug treatments. The effectiveness of immunotherapy, which uses the body's own immune system to fight diseases such as cancer, depends in part upon the ability to "tune" the strength of cellular bonds, for example.

"In many cases, a drug's effectiveness isn't based upon whether or not it binds to a targeted receptor on a cell, but how strongly it binds," said Yan Yu, an assistant professor in the IU Bloomington College of Arts and Sciences' Department of Chemistry, who led the study. "The better we can observe these processes, the better we can screen for the therapeutic effectiveness of a drug."

Until this study, researchers thought particles slowed down and became trapped when they bound to a receptor on a cell.

"But we also saw something new," Yu said. "We saw the particles rotated differently based upon when they became trapped in binding to their receptors."

This has never been seen before because, if molecular motion is a waltz, then scientists were only watching a single dancer.

To conduct their study, Yu's team introduced dance partners. These were two nanoparticles -- one dyed green, the other red -- that paired together to form a single imaging marker visible under a fluorescence microscope. This "nanoprobe" was then camouflaged with a cell membrane coating taken from a T lymphocyte, a type of white blood cell that plays a role in the body's immune system.

The two colors allowed the researchers to simultaneously observe the "rotational motion" -- circling in place -- and "translational motion" -- movement across physical space -- of the particle prior to attaching to the cell.

"We found that the particles began with random rotation, moved to rocking motion, then a circling motion and finally a confined circling motion," Yu said. "The observation of this wide range of rotational motion -- and the transition from one form to the next at different points in time -- is completely new."

Moreover, the researchers were able to start connecting these different motions to different bond strengths.

The group chose to "camouflage" the synthetic particles with cell membranes because these particles are not eliminated by the body's immune system as foreign objects in the same manner as conventional synthetic particles. The use of the body's own cell membranes also eliminates the need to design complicated surface features that bind to specific cells since they're already present in the existing membranes.

Monitoring the "waltzing" of camouflaged T lymphocytes to understand their targeted-binding to tumor cells is the next phase of their research, Yu said.
-end-
Additional authors on the paper are Yanqi Yu, a graduate student at IU, and Yuan Gao, a Ph.D. scientist who was a graduate student at IU at the time of the study. The work was supported by the National Science Foundation and the Research Corporation for Science Advancement.

Indiana University

Related Immune System Articles:

Using the immune system as a defence against cancer
Research published today in the British Journal of Cancer has found that a naturally occurring molecule and a component of the immune system that can successfully target and kill cancer cells, can also encourage immunity against cancer resurgence.
First impressions go a long way in the immune system
An algorithm that predicts the immune response to a pathogen could lead to early diagnosis for such diseases as tuberculosis
Filming how our immune system kill bacteria
To kill bacteria in the blood, our immune system relies on nanomachines that can open deadly holes in their targets.
Putting the break on our immune system's response
Researchers have discovered how a tiny molecule known as miR-132 acts as a 'handbrake' on our immune system -- helping us fight infection.
Decoding the human immune system
For the first time ever, researchers are comprehensively sequencing the human immune system, which is billions of times larger than the human genome.
Masterswitch discovered in body's immune system
Scientists have discovered a critical part of the body's immune system with potentially major implications for the treatment of some of the most devastating diseases affecting humans.
How a fungus can cripple the immune system
An international research team led by Professor Oliver Werz of Friedrich Schiller University, Jena, has now discovered how the fungus knocks out the immune defenses, enabling a potentially fatal fungal infection to develop.
How the immune system protects us against bowel cancer
Researchers from Charité - Universitätsmedizin Berlin have discovered a protective mechanism which is used by the body to protect intestinal stem cells from turning cancerous.
How herpesviruses shape the immune system
DZIF scientists at the Helmholtz Zentrum München have developed an analytic method that can very precisely detect viral infections using immune responses.
The immune system's fountain of youth
Helping the immune system clear away old cells in aging mice helped restore youthful characteristics.
More Immune System News and Immune System Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.