Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Rice unveils ‘green' microcapsule production method

Abstract:
Mix-and-shake procedure leads to instant glass microbubbles

Rice unveils ‘green' microcapsule production method

Houston, TX | May 26, 2005

Chemical engineers from Rice University have developed a fundamentally new approach — the most environmentally sensitive yet devised — for making tiny hollow spheres called microcapsules. Microcapsule research is one of the most active fields in applied nanotechnology, with dozens of companies either developing or using the tiny containers – usually smaller than living cells – to deliver everything from drugs and imaging agents to perfumes and flavor enhancers.

In research appearing on the cover of this month's issue (Vol. 17, Issue. 9) of the journal Advanced Materials, Michael Wong and his research group describe an approach for making microcapsules that involves mixing a solution of polymer and salt with tiny particles of silica that contain just a few hundred atoms apiece.

Microcapsules are typically made by depositing layers of a coating onto a template or core, which has to be removed to form the hollow center of the structure. The core is usually burned out with high heat processes or dissolved with harsh chemicals. Both processes can damage both the microcapsules and their cargo.

“Our process takes place almost instantaneously, at room temperature, under normal pressure, in water, and at mild pH values,” said Wong, assistant professor of chemical and biomolecular engineering, and chemistry. “The spheres naturally become hollow during the self-assembly, which is highly unusual and is an advantage over existing methods.”

Wong's approach has advantages over other microcapsule production methods that involve spraying techniques. While these techniques can be scaled up, it is difficult to adjust the materials properties of the resulting microcapsules.

“We've shown that we can tailor the properties of our self-assembled microcapsules – make them smaller, larger, thicker or thinner – simply by changing the ingredients we start with or by adjusting the mixing procedure,” Wong said. “The underlying chemistry is so easy to perform that anyone who can pour, mix, and shake can make these microcapsules in less than a minute.”

Wong's process involves 'self-assembly,' meaning the hollow spheres form spontaneously when the nanoparticle building blocks are mixed with polymer and salt. Because the process takes place in water, any chemical or drug that's suspended in the water gets trapped inside the hollow sphere when it forms.

Besides encapsulating drugs, flavor compounds and other molecular cargo, Wong's team hopes to develop their microcapsules for drug delivery. They are already exploring ways — like using changes in pH or temperature — to trigger the microcapsules to open and release drugs. In addition, they've made magnetic microcapsules by using iron oxide nanoparticles instead of silica. This could allow doctors to use magnets to precisely position drugs prior to their release.

“We can also use fluorescent nanoparticles called quantum dots to make glowing hollow spheres, which could be useful for combined drug delivery and imaging,” Wong said.

Another potential application includes the delivery of medical imaging agents. For example, most contrast agents that doctors use to improve diagnoses from magnetic resonance imaging are highly toxic. If a small quantity can be sealed away in a microcapsule, safe from contact with any living cells, it could alleviate illness and side effects that patients experience today.

The microcapsules could also be used to encapsulate enzymes, complex biomolecules that that govern many cellular processes. Because enzymes are fragile and expensive, engineers would like to protect them during chemical reactions so they can be used many times over.

Wong's group has shown they can do that to by storing enzymes inside the microcapsules. Their data show that enzymes didn't leak through the walls of the microcapsules, but smaller molecules did, meaning the enzymes could still carry out their prime function and act as a catalyst for chemical reactions. Wong believes the technology could be used to make micro-bioreactors that could be used in large-scale chemical or drug production.

“In comparison with the other methods of making microcapsules, the scale-up for our process is simple and inexpensive,” said Wong. “We believe this gives us a very competitive advantage over competing processes, and a number of companies have expressed an interest in the process.”

Wong's research was funded by Halliburton Energy Services. Oak Ridge Associated Universities, Kraft Foods and Rice University.

####

About Rice:
Rice University is consistently ranked one of America's best teaching and research universities. It is distinguished by its: size - 2,850 undergraduates and 1,950 graduate students; selectivity -10 applicants for each place in the freshman class; resources‹an undergraduate student-to-faculty ratio of 6-to-1, and the fifth largest endowment per student among American universities; residential college system, which builds communities that are both close-knit and diverse; and collaborative culture, which crosses disciplines, integrates teaching and research, and intermingles undergraduate and graduate work. Rice's wooded campus is located in the nation's fourth largest city and on America's South Coast.

Contact:
Jade Boyd
(713) 348-6778
jadeboyd@rice.edu

Copyright © Rice University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

Possible Futures

A novel method for identifying the body’s ‘noisiest’ networks November 19th, 2014

Researchers discern the shapes of high-order Brownian motions November 17th, 2014

VDMA Electronics Production Equipment: Growth track for 2014 and 2015 confirmed: Business climate survey shows robust industry sector November 14th, 2014

Open Materials Development Will Be Key for HP's Success in 3D Printing: HP can make a big splash in 3D printing, but it needs to shore up technology claims and avoid the temptation of the razor/razor blade business model in order to flourish November 11th, 2014

Self Assembly

Revealed: How bacteria drill into our cells and kill them December 2nd, 2014

Live Images from the Nano-cosmos: Researchers watch layers of football molecules grow November 5th, 2014

Outsmarting Thermodynamics in Self-assembly of Nanostructures: Berkeley Lab reports method for symmetry-breaking in feedback-driven self-assembly of optical metamaterials November 4th, 2014

NYU Researchers Break Nano Barrier to Engineer the First Protein Microfiber October 23rd, 2014

Nanomedicine

Zenosense, Inc. - Hospital Collaboration - 400 Person Lung Cancer Detection Trial December 17th, 2014

Unraveling the light of fireflies December 17th, 2014

First Home-Made Edible Herbal Nanodrug Presented to Pharmacies across Iran December 17th, 2014

Nanomedicine expert joins Rice faculty: Gang Bao combines genetic, nano and imaging techniques to fight disease December 17th, 2014

Announcements

Switching to spintronics: Berkeley Lab reports on electric field switching of ferromagnetism at room temp December 17th, 2014

ORNL microscopy pencils patterns in polymers at the nanoscale December 17th, 2014

Unraveling the light of fireflies December 17th, 2014

First Home-Made Edible Herbal Nanodrug Presented to Pharmacies across Iran December 17th, 2014

Environment

Nanoparticles Prove Effective in Removing Phosphor from Calcareous Soil December 10th, 2014

Detecting gases wirelessly and cheaply: New sensor can transmit information on hazardous chemicals or food spoilage to a smartphone December 8th, 2014

Nanocatalysts Can Reduce Pollution Caused by Diesel Engines December 4th, 2014

Green meets nano: Scientists at TU Darmstadt create multifunctional nanotubes using nontoxic materials December 3rd, 2014

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE