Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

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 nano-roundabout for light December 10th, 2016

Keeping electric car design on the right road: A closer look at the life-cycle impacts of lithium-ion batteries and proton exchange membrane fuel cells December 9th, 2016

Further improvement of qubit lifetime for quantum computers: New technique removes quasiparticles from superconducting quantum circuits December 9th, 2016

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D: Up-close, real-time, chemical-sensitive 3-D imaging offers clues for reducing cost/improving performance of catalysts for fuel-cell-powered vehicles and other applications December 8th, 2016

Self Assembly

Computers made of genetic material? HZDR researchers conduct electricity using DNA-based nanowires November 9th, 2016

First multicellular organism inspires the design of better cancer drugs September 15th, 2016

A versatile method to pattern functionalized nanowires: A team of researchers from Hokkaido University has developed a versatile method to pattern the structure of 'nanowires,' providing a new tool for the development of novel nanodevices September 9th, 2016

Location matters in the self-assembly of nanoclusters: Iowa State University scientists have developed a new formulation to explain an aspect of the self-assembly of nanoclusters on surfaces that has broad applications for nanotechnology September 8th, 2016

Nanomedicine

Arrowhead Pharmaceuticals to Webcast Fiscal 2016 Year End Results December 7th, 2016

Fast, efficient sperm tails inspire nanobiotechnology December 5th, 2016

Journal Nanotechnology Progress International (JONPI) Volume 6, issue 2 coming out soon! December 5th, 2016

UTSA study describes new minimally invasive device to treat cancer and other illnesses: Medicine diffusion capsule could locally treat multiple ailments and diseases over several weeks December 3rd, 2016

Announcements

A nano-roundabout for light December 10th, 2016

Keeping electric car design on the right road: A closer look at the life-cycle impacts of lithium-ion batteries and proton exchange membrane fuel cells December 9th, 2016

Further improvement of qubit lifetime for quantum computers: New technique removes quasiparticles from superconducting quantum circuits December 9th, 2016

Chemical trickery corrals 'hyperactive' metal-oxide cluster December 8th, 2016

Environment

Keeping electric car design on the right road: A closer look at the life-cycle impacts of lithium-ion batteries and proton exchange membrane fuel cells December 9th, 2016

Semiconductor-free microelectronics are now possible, thanks to metamaterials November 9th, 2016

First time physicists observed and quantified tiny nanoparticle crossing lipid membrane November 7th, 2016

Nanosensors on the alert for terrorist threats: Scientists interested in the prospects of gas sensors based on binary metal oxide nanocomposites November 5th, 2016

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