Scientists use laser imaging to assess safety of zinc oxide nanoparticles in sunscreen

ScienceDaily (Nov. 30, 2011) — Ultra-tiny zinc oxide (ZnO) particles with dimensions less than one-ten-millionth of a meter are among the ingredients list of some commercially available sunscreen products, raising concerns about whether the particles may be absorbed beneath the outer layer of skin. To help answer these safety questions, an international team of scientists from Australia and Switzerland have developed a way to optically test the concentration of ZnO nanoparticles at different skin depths. They found that the nanoparticles did not penetrate beneath the outermost layer of cells when applied to patches of excised skin.

The results, which were published this month in the Optical Society's (OSA) open-access journal Biomedical Optics Express, lay the groundwork for future studies in live patients.

The high optical absorption of ZnO nanoparticles in the UVA and UVB range, along with their transparency in the visible spectrum when mixed into lotions, makes them appealing candidates for inclusion in sunscreen cosmetics. However, the particles have been shown to be toxic to certain types of cells within the body, making it important to study the nanoparticles' fate after being applied to the skin. By characterizing the optical properties of ZnO nanoparticles, the Australian and Swiss research team found a way to quantitatively assess how far the nanoparticles might migrate into skin.

The team used a technique called nonlinear optical microscopy, which illuminates the sample with short pulses of laser light and measures a return signal. Initial results show that ZnO nanoparticles from a formulation that had been rubbed into skin patches for 5 minutes, incubated at body temperature for 8 hours, and then washed off, did not penetrate beneath the stratum corneum, or topmost layer of the skin. The new optical characterization should be a useful tool for future non-invasive in vivo studies, the researchers write.

Recommend this story on Facebook, Twitter,
and Google +1:

Other bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by Optical Society of America.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

Zhen Song, Timothy A. Kelf, Washington H. Sanchez, Michael S. Roberts, Jaro Ricka, Martin Frenz, Andrei V. Zvyagin. Characterization of optical properties of ZnO nanoparticles for quantitative imaging of transdermal transport. Biomedical Optics Express, 2011; 2 (12): 3321 DOI: 10.1364/BOE.2.003321

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Read More

A revolutionary new 'dry ink' for laser printers and photocopy machines

ScienceDaily (Nov. 30, 2011) — Imagine someone inventing a "super-toner," a revolutionary new "dry ink" for copiers and laser printers that produces higher-quality, sharper color images more economically, cutting electricity by up to 30 percent. One that also reduces emissions of carbon dioxide -- the main greenhouse gas -- in the production of tens of thousands of tons of toner produced each year. One that reduces the cost of laser printing, making it more affordable in more offices, schools and homes.

Sound like a toner that is too good to be true? Well, a team of scientists at the Xerox Corporation actually invented it. A new episode in the 2011 edition of a  video series from the American Chemical Society (ACS), the world's largest scientific society, focuses on the research and the teamwork that led to this advance.

Titled Prized Science: How the Science Behind ACS Awards Impacts Your Life, the videos are available without charge at the Prized Science website and on DVD.

ACS encourages educators, schools, museums, science centers, news organizations and others to embed links to Prized Science on their websites. The videos discuss scientific research in non-technical language for general audiences. New episodes in the series, which focuses on ACS' 2011 award recipients, will be issued in November and December.

"Science awards shine light on individuals who have made impressive achievements in research," noted ACS President Nancy B. Jackson, Ph.D. "Often, the focus is on the recipients, with the public not fully grasping how the award-winning research improves the everyday lives of people around the world. The Prized Science videos strive to give people with no special scientific knowledge the chance to discover the chemistry behind the American Chemical Society's national awards and see how it improves and transforms our daily lives."

A Revolutionary New "Dry Ink" for Laser Printers & Photocopy Machines features the research of Patricia Burns, Ph.D., Grazyna Kmiecik-Lawrynowicz, Ph.D., Chieh-Min Cheng, Ph.D., and Tie Hwee Ng, Ph.D., winners of the 2011 ACS Award for Team Innovation sponsored by the ACS Corporation Associates. Toner is the fine powder used instead of ink in photocopy machines, laser printers and multifunction devices -- machines that print, copy and fax. The researchers at Xerox developed a new toner called "EA Toner," which stands for "emulsion aggregation." They start with a liquid material that looks like house paint. That's the "emulsion" part. Then, they throw in pigments for color, waxes and other useful things and let everything "aggregate," or stick together. Then, it all dries out, and what's left is a fine powder that they can put into a toner cartridge. That worked fine in the lab, but scaling it up to produce millions of toner cartridges to meet consumers' demands was difficult -- all of the scientists had to work together to make the new toner a commercial reality.

Recommend this story on Facebook, Twitter,
and Google +1:

Other bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by American Chemical Society.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Read More

Laser Hair Removal Manhattan

Welcome to Manhattan's most experienced laser hair removal center! A pioneer in New York, using the world's most advanced and powerful lasers for all skin types, Manhattan Laser Hair Removal provides safe, affordable, fast and efficient permanent hair reduction. FDA cleared for permanent hair removal, both of our lasers permanently eliminate ingrowns in all skin types, including tanned skin. Our technicians are experienced and professional, our approach honest and reliable.
Manhattan Laser Hair Removal Center has grown into a full service medical spa, offering permanent laser hair removal services along with botox, vitamin treatments, vascular vein treatments, and a whole new NATURAL product line from physician supervised elements medical spa with Dr. Robert L Pastore PHD and c as medical directors in New York City.

We are open 6 days a week and offer Free Consultation for LASER HAIR REMOVAL. Our staff is fully certified, discreet and professional. We also carry a new NATURAL product line for all your cosmetic needs
Manhattan Laser Hair Removal is the best value for your money in laser hair removal services. Here is what you should expect from us:

• Free, thorough and honest consultation
• No waiting time with appointments
• No rush
• Professional and courteous attitude and concern for your well-being
• Clean and efficient facilities
• Thorough treatments
• Fair and competitive pricing and several payment options

Read More