Featured Research

from universities, journals, and other organizations

PEBBLEs Help U-M Scientists Open A Window On Cell Chemistry

Date:
March 13, 1998
Source:
University Of Michigan
Summary:
University of Michigan researchers have found a way to monitor changes in the biochemistry of living cells by shooting the cells full of PEBBLEs. Made of polymers, instead of stone, PEBBLEs (Probes Encapsulated By BioListic Embedding) are the smallest biosensors ever developed.

ANN ARBOR---University of Michigan researchers have found a way to monitor changes in the biochemistry of living cells by shooting the cells full of PEBBLEs.

Made of polymers, instead of stone, PEBBLEs (Probes Encapsulated By BioListic Embedding) are the smallest biosensors ever developed, according to Raoul Kopelman, the U-M's Kasimir Fajans Professor of Chemistry, Physics and Applied Physics. They were designed to work inside mammalian cells where they can detect subtle changes in concentrations of ions and small molecules.

"PEBBLEs are self-contained sensors powerful enough to detect even slight changes in cell biochemistry, but small enough to avoid damaging the cell," said Heather Clark, a U-M graduate student in chemistry. Clark is part of a U-M team currently developing and testing the biosensing devices in a research project funded by the U.S. Defense Advanced Research Projects Agency (DARPA).

Clark will present results from her research this week in a presentation at PITTCON '98, the Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy, taking place in New Orleans.

"For the first time, we can observe real-time chemical processes inside a living cell," said Kopelman. "The goal of the DARPA project is to learn what happens inside the cell when it is exposed to neurotoxic agents. If we can learn exactly how these toxins trigger a flood of ions in and out of cells, we may be able to speed up development of antidotes or countermeasures for lethal biological warfare agents."

Kopelman added that the ability to "watch what's happening inside a cell," has a wide variety of potential applications in other fields---including cancer therapy, glucose monitoring, drug or chemical toxicity testing, and all areas of biosensing.

Kopelman says Clark has fabricated PEBBLEs as small as 20 nanometers in diameter. That's 100,000 times smaller than the letter "n" in this sentence. The tiny polymer spheres contain many surface pores. When Clark adds dyes to a polymer microemulsion suspension during pebble fabrication, the dyes are naturally taken up by the PEBBLE's pores.

According to Clark, each dye is specific for, or will bind to, just one type of ion or molecule. So far, she has produced PEBBLEs specific for calcium, oxygen, magnesium and pH---the acidity level in a solution. When a PEBBLE is exposed to even very small quantities of its target substance, the dye in the PEBBLE glows when activated by a specific wavelength of light. As the concentration of the targeted substance changes, the intensity of the PEBBLE's fluorescence increases or decreases.

Once the PEBBLEs are ready, Clark uses pico-injection techniques or a gene gun to fire them randomly into human or mouse cells in a culture dish. "The PEBBLEs blast through the cell membrane like bullets," Clark explains, "but because they are so small, they rarely do any damage. Mortality of cells shot with PEBBLEs is only two percent higher than in control cells."

Martin A. Philbert, U-M assistant professor of toxicology in the School of Public Health, has directed toxicology tests on several types of PEBBLE-containing cells and agrees that PEBBLEs can be inserted with far less trauma to the cell than is produced by free dyes or fiberoptic probes. Philbert and Marion Hoyer, a U-M research fellow, will present results from these toxicology tests this week at the Society of Toxicology annual meeting in Seattle, Wash.

Others currently involved in the research project include Brian Athey, assistant professor of anatomy and cell biology in the U-M Medical School; U-M graduate students Alex Ade, Murphy Brasuel and Michael Miller; and U-M research fellows Steve Parus and Zhong-You Shi, U-M research fellow in chemistry. The U-M has applied for a patent on its PEBBLE technology.


Story Source:

The above story is based on materials provided by University Of Michigan. Note: Materials may be edited for content and length.


Cite This Page:

University Of Michigan. "PEBBLEs Help U-M Scientists Open A Window On Cell Chemistry." ScienceDaily. ScienceDaily, 13 March 1998. <www.sciencedaily.com/releases/1998/03/980313023655.htm>.
University Of Michigan. (1998, March 13). PEBBLEs Help U-M Scientists Open A Window On Cell Chemistry. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/1998/03/980313023655.htm
University Of Michigan. "PEBBLEs Help U-M Scientists Open A Window On Cell Chemistry." ScienceDaily. www.sciencedaily.com/releases/1998/03/980313023655.htm (accessed July 23, 2014).

Share This




More Health & Medicine News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Courts Conflicted Over Healthcare Law

Courts Conflicted Over Healthcare Law

AP (July 22, 2014) Two federal appeals courts issued conflicting rulings Tuesday on the legality of the federally-run healthcare exchange that operates in 36 states. (July 22) Video provided by AP
Powered by NewsLook.com
Why Do People Believe We Only Use 10 Percent Of Our Brains?

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Newsy (July 22, 2014) The new sci-fi thriller "Lucy" is making people question whether we really use all our brainpower. But, as scientists have insisted for years, we do. Video provided by Newsy
Powered by NewsLook.com
Scientists Find New Way To Make Human Platelets

Scientists Find New Way To Make Human Platelets

Newsy (July 22, 2014) Boston scientists have discovered a new way to create fully functioning human platelets using a bioreactor and human stem cells. Video provided by Newsy
Powered by NewsLook.com
Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

TheStreet (July 21, 2014) New research shows Gilead Science's drug Sovaldi helps in curing hepatitis C in those who suffer from HIV. In a medical study, the combination of Gilead's Hep C drug with anti-viral drug Ribavirin cured 76% of HIV-positive patients suffering from the most common hepatitis C strain. Hepatitis C and related complications have been a top cause of death in HIV-positive patients. Typical medication used to treat the disease, including interferon proteins, tended to react badly with HIV drugs. However, Sovaldi's %1,000-a-pill price tag could limit the number of patients able to access the treatment. TheStreet's Keris Lahiff reports from New York. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins