Featured Research

from universities, journals, and other organizations

Squishy hydrogels may be the ticket for studying biological effects of nanoparticles

Date:
May 15, 2013
Source:
National Institute of Standards and Technology (NIST)
Summary:
A class of water-loving, jelly-like materials with uses ranges ranging from the mundane, such as superabsorbent diaper liners, to the sophisticated, such as soft contact lenses, could be tapped for a new line of serious work: testing the biological effects of nanoparticles, according to scientists.

After four days, quantum dots still shine (green) in cells embedded in a hydrogel scaffold.
Credit: Mansfield/NIST

A class of water-loving, jelly-like materials with uses ranges ranging from the mundane, such as superabsorbent diaper liners, to the sophisticated, such as soft contact lenses, could be tapped for a new line of serious work: testing the biological effects of nanoparticles now being eyed for a large variety of uses.

New research by scientists at the National Institute of Standards and Technology (NIST) demonstrates that three-dimensional scaffolds made with cells and supporting materials known as hydrogels can serve as life-like measurement platforms for evaluating how tiny engineered materials interact with cells and tissues. Their proof-of-concept study suggests that hydrogel tissue scaffolds can be a "powerful bridge" between current laboratory tests and tests that use animal models.

Today, laboratory tests of nanoparticles usually entail exposing a two-dimensional layer of cells to the material of interest. Besides being questionable substitutes for the complex cellular frameworks that make up tissues and organs inside the body, these tests can yield conflicting results, explains analytical chemist Elisabeth Mansfield, lead researcher on the new NIST study.

"Our study shows that hydrogel-based, tissue-engineering scaffolds can provide more realistic environments to study nanoparticle-influenced cell biology over extended periods," she says. Importantly, the NIST research shows that studies employing the scaffold do not require exposing cells to nanoparticles in doses that exceed normal exposure levels.

Hydrogels are networks of stringy, branching polymer molecules with ends that latch onto water molecules -- so much so that 99.9 percent of a hydrogel may consist of water. Depending on the spacing between the strands (the so-called mesh size) and other factors, hydrogels can support and promote the growth and differentiation of cell populations.

While hydrogels occur naturally -- an example is cartilage -- the NIST team chose to craft its own, giving them control over the mesh size in the scaffolds they created.

In their experiment, the team used polyethylene glycol -- a common polymer used in skin creams, toothpaste, lubricants and other products -- to create three hydrogels with different mesh sizes. One set of hydrogels was populated with rat cells containing ultrasmall semiconducting materials known as quantum dots. When exposed to light, quantum dots emit strong fluorescent signals that enabled the researchers to track the fate of treated cells in the synthetic scaffolds.

Results were compared with those for similarly treated cells grown in a single layer on a substrate, akin to standard laboratory toxicology tests.

The NIST researchers found that cells diffused through the hydrogel scaffold, forming a persisting tissue-like structure. Quantum dots attached to cell membranes and, over time, were absorbed into the cells.

Three-dimensional scaffolds often are used to test cells for multi-week experiments, and NIST researchers found quantum dots can be detected for four or more days inside the scaffold.

As significant, cells that populated the hydrogel scaffolds were exposed to lower levels of quantum dots, yielding a more representative scenario for evaluating biological effects.

The NIST team concludes that, compared with conventional cell cultures, hydrogel scaffolds provide a more realistic, longer-lived biological environment for studying how engineering nanoparticles interact with cells. In addition, the scaffolds will accommodate studies of how these interactions evolve over time and of how the physical features of nanoparticles may change.


Story Source:

The above story is based on materials provided by National Institute of Standards and Technology (NIST). Note: Materials may be edited for content and length.


Journal Reference:

  1. Elisabeth Mansfield, Tammy L. Oreskovic, Nikki S. Rentz, Kavita M. Jeerage. Three-dimensional hydrogel constructs for exposing cells to nanoparticles. Nanotoxicology, 2013; DOI: 10.3109/17435390.2013.790998

Cite This Page:

National Institute of Standards and Technology (NIST). "Squishy hydrogels may be the ticket for studying biological effects of nanoparticles." ScienceDaily. ScienceDaily, 15 May 2013. <www.sciencedaily.com/releases/2013/05/130515125116.htm>.
National Institute of Standards and Technology (NIST). (2013, May 15). Squishy hydrogels may be the ticket for studying biological effects of nanoparticles. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2013/05/130515125116.htm
National Institute of Standards and Technology (NIST). "Squishy hydrogels may be the ticket for studying biological effects of nanoparticles." ScienceDaily. www.sciencedaily.com/releases/2013/05/130515125116.htm (accessed July 31, 2014).

Share This




More Plants & Animals News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
Powered by NewsLook.com
Concern Grows Over Worsening Ebola Crisis

Concern Grows Over Worsening Ebola Crisis

AFP (July 30, 2014) Pan-African airline ASKY has suspended all flights to and from the capitals of Liberia and Sierra Leone amid the worsening Ebola health crisis, which has so far caused 672 deaths in Guinea, Liberia and Sierra Leone. Duration: 00:43 Video provided by AFP
Powered by NewsLook.com
At Least 20 Chikungunya Cases in New Jersey

At Least 20 Chikungunya Cases in New Jersey

AP (July 30, 2014) At least 20 New Jersey residents have tested positive for chikungunya, a mosquito-borne virus that has spread through the Caribbean. (July 30) Video provided by AP
Powered by NewsLook.com
Xtreme Eating: Your Daily Caloric Intake All On One Plate

Xtreme Eating: Your Daily Caloric Intake All On One Plate

Newsy (July 30, 2014) The Center for Science in the Public Interest released its 2014 list of single meals with whopping calorie counts. Video provided by Newsy
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