Navigation Links
'Instant acid' method offers new insight into nanoparticle dispersal in the environment and the body
Date:6/9/2010

Using a chemical trick that allows them to change the acidity of a solution almost instantly, a team at the National Institute of Standards and Technology (NIST) has demonstrated a simple and effective technique for quantifying how the stability of nanoparticle solutions change when the acidity of their environment suddenly changes*. The measurement method and the problem studied are part of a broader effort at NIST to understand the environmental, health and safety implications of nanoparticles.

Any change in nanoparticle solubility with local acidity (pH**) ultimately affects how they are distributed in the environment as well as their potential for uptake into organisms. This is crucial when designing nanoparticles for use in medicine, explains NIST chemical engineer Vivek Prabhu. "Cells in the body are very compartmentalized. There are places within the cell that have vastly different pH. For instance, in the sea of the cell, the cytosol, pH is regulated to be about 7.2, which is slightly basic. But within the lysosome, which is where things go to get broken down, the pH is about 4.5, so it's very acidic."

Nanoparticles designed for use in drug therapy or as contrast agents for medical imaging typically are coated with molecules to prevent the particles from clumping together, which would reduce their effectiveness. But the efficacy of the anti-clumping coating often depends on the pH of the environment. According to the NIST team, while it's relatively easy to put nanoparticles in a solution at a particular pH and to study the stability of the suspension over long times, it is difficult to tell what happens when the particles are suddenly exposed to a different level of acidity as often occurs in environmental and application contexts. How long does it take them to react to this change and how?

"Our idea borrows some of the materials used in photolithography to make microcircuits," says Prabhu. "There are molecules that become acids when you shine a light on themphoto acid generators. So instead of manually pouring acid into a solution and stirring it around, you start with a solution in which these molecules already are mixed and dissolved. Once you shine light on it bam! Photolysis occurs and it becomes acidic." The acidity of the solution can be made to jump a major stepan amount chosen by the experimenterwithout needing to wait for mixing or disturbing the solution. "It gives you a way to probe the nanoparticle solution dynamics at much shorter timescales than before," says Prabhu.

Using their "instant acid" technique and light scattering instruments to monitor the aggregation of nanoparticles, the NIST team followed the growth of clusters of chemically stabilized latex nanoparticles for the first few seconds after inducing the pH transition with light. Their results demonstrate that under certain conditions, the stability of the nanoparticlestheir tendency to resist clumpingbecomes very sensitive to pH. Studies such as these could provide a stronger foundation to design nanoparticles for applications such as targeting tumor cells that have levels of acidity markedly different from normal cells.


'/>"/>

Contact: Michael Baum
michael.baum@nist.gov
301-975-2763
National Institute of Standards and Technology (NIST)
Source:Eurekalert  

Related biology news :

1. Small liquid sensor may detect cancer instantly, could lead to home detection kit
2. Bamboo instant houses will soon shelter Sichuan quake victims
3. Europes scientists call for more effort in tackling rising ocean acidity
4. Folic acid found to improve vascular function in amenorrheic runners
5. Weird, ultra-small microbes turn up in acidic mine drainage
6. U of I study: Lack of omega-3 fatty acid linked to male infertility
7. U of I study: Lack of omega-6 fatty acid linked to severe dermatitis
8. Ecosystems under threat from ocean acidification
9. How much omega-3 fatty acid do we need to prevent cardiovascular disease?
10. American Society for Microbiology honors Angelika Gruendling for work on lipoteichoic acids
11. University of Hawaii at Manoa researchers reveal ocean acidification at Station ALOHA
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
'Instant acid' method offers new insight into nanoparticle dispersal in the environment and the body
(Date:3/31/2016)...   LegacyXChange, Inc. ... LegacyXChange is excited to release its first ... be launched online site for trading 100% guaranteed authentic ... also provide potential shareholders a sense of the value ... industry that is notorious for fraud. The video is ...
(Date:3/22/2016)... , March 22, 2016 ... research report "Electronic Sensors Market for Consumer Industry by ... & Others), Application (Communication & IT, Entertainment, ... - Global Forecast to 2022", published by ... is expected to reach USD 26.76 Billion ...
(Date:3/17/2016)... , March 17, 2016 ABI Research, ... forecasts the global biometrics market will reach more ... 118% increase from 2015. Consumer electronics, particularly smartphones, ... fingerprint sensors anticipated to reach two billion shipments ... Dimitrios Pavlakis , Research Analyst at ABI ...
Breaking Biology News(10 mins):
(Date:4/29/2016)... , ... April 29, 2016 , ... ... necessary fundamentals to transform technology into a viable company, CereScan’s CEO, John Kelley, ... Mr. Kelley, a recognized leader and mentor in the Denver area business community, ...
(Date:4/28/2016)... YORK , April 28, 2016 ... acceleration company reports the Company,s CEO  was featured ... titled Accelerators Enter When VCs Fear To Tread: ... Science Leader magazine is an essential ... for everything from emerging biotechs to Big Pharmas. ...
(Date:4/27/2016)... ... April 27, 2016 , ... Cambridge Semantics, ... web technology, today announced that it has been named to The Silicon Review’s “20 ... services and other markets, Cambridge Semantics serves the needs of end users facing some ...
(Date:4/27/2016)... SILVER SPRING, Md. and RESEARCH ... -- United Therapeutics Corporation (NASDAQ: UTHR ) announced ... Co-Chief Executive Officer, of United Therapeutics will provide an ... Deutsche Bank 41 st Annual Health Care Conference. ... May 5, 2016, at 10:00 a.m. Eastern Time, and ...
Breaking Biology Technology: