Navigation Links
Shape-shifting nanoparticles flip from sphere to net in response to tumor signal
Date:5/28/2013

Scientists at the University of California, San Diego, have designed tiny spherical particles to float easily through the bloodstream after injection, then assemble into a durable scaffold within diseased tissue. An enzyme produced by a specific type of tumor can trigger the transformation of the spheres into netlike structures that accumulate at the site of a cancer, the team reports in the journal Advanced Materials this week.

Targeting treatments specifically to cancerous or other diseased cells depends on some means of accumulating high levels of a drug or other therapeutic agent at the specific site and keeping it there. Most efforts so far depend on matching a piece of the drug-delivering molecule to specific receptors on the surface of the target cell.

Inspiration for this new strategy came from biological systems that use shape to alter the ability of something to lock in place or slip away and escape, said Nathan Gianneschi, a professor of chemistry and biochemistry, who led the project.

"We wanted to come up with a new approach," Gianneschi said. "Specifically, we wanted to design switchable materials that we could inject in one shape and have them change to another between the blood and tumors."

Some cancerous tissues produce high levels of a class of molecules called MMPs, for matrix metalloproteinases. These enzymes change how other proteins behave by altering their molecular configuration, leading to metastasis. Gianneschi and colleagues harnessed this ability to alter their nanoparticles in ways that would cause them to linger at the site of the tumor.

"We figured out how to make an autonomous material that could sense its environment and change accordingly," Gianneschi said.

Each nanoparticle is made of many detergent-like molecules with one end that mixes readily with water and another that repels it. In solution, they self assemble into balls with the water-repellant ends inside, and in that configuration can easily be injected into a vein.

When mixed with MMPs in vials, the enzymes nicked the peptides on the surface of the spheres, which reassembled into netlike threads.

The team tested the concept further by injecting their new nanoparticles into mice with human fibrosarcomas, a kind of cancer that produces high levels of MMPs.

To mark when the spheres broke down to form other structures, the chemists placed one of two fluorecent dyes, rhodamine or fluorescein, inside the spheres. In close proximity, the dyes interact to create a specific light signal called FRET for Frster Resonance Energy Transfer, when energy jumps from rhodamine to fluorescein.

Within a day they detected FRET signals indicating that the spheres had reassembled at the sites of the tumors, and the signal persisted for at least a week.

The treatment is not inherently toxic. It did not appear to change the tumors in any way, and liver and kidney, the organs most vulnerable to collateral damage from treatments because they clear toxins from the body, were normal and healthy eight days after injection.

Different versions of these nanoparticles could be designed to respond to signals inherent to other types of cancers and inflamed tissue, the authors say. The spheres can also be engineered to carry drugs, or different diagnostic probes.

Right now, this same team is developing nanoparticles that carry an infrared dye, which would enable them to visualize tumors deeper inside the body along with other materials that can be imaged with instruments commonly available in the clinic.


'/>"/>

Contact: Susan Brown
scinews@ucsd.edu
858-246-0161
University of California - San Diego
Source:Eurekalert

Related medicine news :

1. Mayo Clinic: How gold nanoparticles can help fight ovarian cancer
2. New technique can help nanoparticles deliver drug treatments
3. Nanoparticles loaded with bee venom kill HIV
4. Researchers show that lipid nanoparticles are ideal for delivering genes and drugs
5. New electrically-conductive polymer nanoparticles can generate heat to kill colorectal cancer cells
6. UGA researchers boost efficacy of drugs by using nanoparticles to target powerhouse of cells
7. Nanoparticles detect biochemistry of inflammation
8. Improved nanoparticles deliver drugs into brain
9. UCSB scientists examine effects of manufactured nanoparticles on soybean crops
10. New nanoparticles shrink tumors in mice
11. Researchers find gold nanoparticles capable of unzipping DNA
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:10/13/2017)... ... October 13, 2017 , ... As health professionals work to improve their approach ... patient is doing more than filling out a survey; in many cases health professionals ... emphasis in health care and research on the importance of active engagement with patients ...
(Date:10/13/2017)... ... October 13, 2017 , ... ... ‘17, and Jennifer Huggins, PharmD ’17, along with clinical associate professor Janice ... of cardiovascular diseases during the 15th Annual Women’s Health Conference. The SIU ...
(Date:10/13/2017)... ... , ... Ellevate Network, the leading network for professional women, brought together some ... at their inaugural Summit in New York City in June. The event was livestreamed ... over 3 million. To watch the Mobilize Women video, click here . ...
(Date:10/13/2017)... ... October 13, 2017 , ... “The Journey: From the Mountains to ... to save lost souls in the Philippines. “The Journey: From the Mountains to the ... teacher of the Bible. She has taught all ages and currently teaches a class ...
(Date:10/12/2017)... ... October 12, 2017 , ... The company has developed ... consumer and regulatory authorities worldwide. From Children’s to Adults 50+, every formula has ... highest standard. , These products are also: Gluten Free, Non-GMO, Vegan, Soy ...
Breaking Medicine News(10 mins):
(Date:9/27/2017)... and NEW YORK , Sept. 27, 2017 ... mobile health and big data solutions, today announced that its MyDario product ... check your local TV listings for when The Dr. Oz Show airs ... The ... this month. ...
(Date:9/23/2017)... -- Janssen Biotech, Inc. (Janssen) announced today that it ... Food and Drug Administration (FDA) for the Biologics License ... of moderately to severely active rheumatoid arthritis (RA). The ... to further evaluate the safety of sirukumab in the ... "We are disappointed by ...
(Date:9/19/2017)... HistoSonics, Inc., a venture-backed medical device company developing a non-invasive, robotically assisted, platform therapy that ... developments today:   ... ... Tom Tefft ... Veteran medical device executive Josh Stopek , PhD, who has led R&D and ...
Breaking Medicine Technology: