Technology in common household humidifiers could enable the next wave of high-tech medical imaging and targeted medicine, thanks to a new method for making tiny silicone microspheres developed by chemists at the University of Illinois.
Led by chemistry professor Kenneth Suslick, the researchers published their results in the journal Advanced Science.
Microspheres, tiny spheres as small as a red blood cell, have shown promise as agents for targeted drug delivery to tissues, as contrast agents for medical imaging, and in industrial applications.
One prime contender as a material for microspheres is silicone, the rubbery plastic found in everything from bathtub caulk to kitchenware to medical implants, but a method of making silicone into microspheres has eluded scientists.
Silicone owes its versatility to its unique combination of properties: It is biocompatible, heat resistant, chemically stable, waterproof and environmentally benign. Yet some of those same qualities have frustrated researchers attempting to make silicone microspheres.
The traditional microsphere-making method of suspending tiny droplets of material in another liquid does not work with silicone.
"For silicone, creating a stable emulsion of small droplets is very difficult," Suslick said. "Even if a stable emulsion is achieved, you run into even bigger problems when it is heated, which is necessary to polymerize into solid spheres. Upon heating, small droplets of silicone starting material will coalesce with other droplets and produce only bigger spheres."
The Illinois team uses a technique called ultrasonic spray pyrolysis, which employs technology found in household humidifiers to create a mist of ultrafine droplets. Suslick's group has pioneered the technique for a variety of materials, and teamed up with U. of I. chemistry professor Catherine Murphy to tackle the problem of silicone.
The researchers send a mist containing all the ingredients of silicone through a heated tube, which solidifies the mist into tiny spheres of silicone. Because the droplets are all separate within the mist, they don't stick together like they do in an emulsion, so the resulting microspheres are roughly 100 times smaller than any previously reported.
The researchers made silicone microspheres with a variety of properties for different applications, including colored, fluorescent and magnetic spheres. Because the spheres are bio-inert - they do not react with chemicals in the body - and the researchers believe they would be excellent vessels for extended-release pharmaceuticals. They are also exploring potential applications of solid, hollow and magnetic microspheres.
"The applications for silicone microspheres, to date, have been almost entirely speculative, simply because no one has been able to actually make them," said Jacqueline Rankin, the lead graduate student on this project. "With this new method, silicone microspheres can be easily and readily synthesized, facilitating the exploration of technologies that have only been speculated upon and creating novel technologies and new science in a number of scientific disciplines."
Graduate students Nitin Neelakantan, Elissa Grzincic and Kimberly Lundberg were co-authors of the paper. The work was supported by the National Science Foundation, National Institutes of Health, James R. Beck Fellowship, and the Robert C. and Carolyn J. Springborn Endowment.
Editor's note: To reach Ken Suslick, call 217-333-2794; email: email@example.com.
The paper, "Magnetic, Fluorescent, and Copolymeric Silicone Microspheres," is available online at http://onlinelibrary.
Liz Ahlberg | EurekAlert!
Another piece of Ebola virus puzzle identified
17.01.2019 | Texas Biomedical Research Institute
New scale for electronegativity rewrites the chemistry textbook
17.01.2019 | Chalmers University of Technology
World first experiments on sensor that may revolutionise everything from medical devices to unmanned vehicles
The new sensor - capable of detecting vibrations of living cells - may revolutionise everything from medical devices to unmanned vehicles.
Dead and alive at the same time? Researchers at the Max Planck Institute of Quantum Optics have implemented Erwin Schrödinger’s paradoxical gedanken experiment employing an entangled atom-light state.
In 1935 Erwin Schrödinger formulated a thought experiment designed to capture the paradoxical nature of quantum physics. The crucial element of this gedanken...
Cellulose obtained from wood has amazing material properties. Empa researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing.
It all starts with an ear. Empa researcher Michael Hausmann removes the object shaped like a human ear from the 3D printer and explains:
The phenomenon of so-called superlubricity is known, but so far the explanation at the atomic level has been missing: for example, how does extremely low friction occur in bearings? Researchers from the Fraunhofer Institutes IWM and IWS jointly deciphered a universal mechanism of superlubricity for certain diamond-like carbon layers in combination with organic lubricants. Based on this knowledge, it is now possible to formulate design rules for supra lubricating layer-lubricant combinations. The results are presented in an article in Nature Communications, volume 10.
One of the most important prerequisites for sustainable and environmentally friendly mobility is minimizing friction. Research and industry have been dedicated...
Just in time for Christmas, a Mars-analogue mission in Morocco, coordinated by the Robotics Innovation Center of the German Research Center for Artificial Intelligence (DFKI) as part of the SRC project FACILITATORS, has been successfully completed. SRC, the Strategic Research Cluster on Space Robotics Technologies, is a program of the European Union to support research and development in space technologies. From mid-November to mid-December 2018, a team of more than 30 scientists from 11 countries tested technologies for future exploration of Mars and Moon in the desert of the Maghreb state.
Close to the border with Algeria, the Erfoud region in Morocco – known to tourists for its impressive sand dunes – offered ideal conditions for the four-week...
16.01.2019 | Event News
14.01.2019 | Event News
12.12.2018 | Event News
17.01.2019 | Physics and Astronomy
17.01.2019 | Materials Sciences
17.01.2019 | Information Technology