The polymers can be made from natural materials such as proteins or from human-made substances to make plastic, rubber or fibre.
The new method, dubbed magnetospinning by researchers at the University of Georgia, is said to provide a simple, scalable and safe means for producing large quantities of nanofibres that can be embedded with materials such as live cells and drugs.
“The process we have developed makes it possible for almost anyone to manufacture high-quality nanofibres without the need for expensive equipment,” said Sergiy Minko, study co-author and the Georgia Power Professor of Polymers, Fibres and Textiles at the College of Family and Consumer Sciences.
“This not only reduces costs, but it also makes it possible for more businesses and researchers to experiment with nanofibres without worrying too much about their budget,” he said in a statement.
Many thousands of times thinner than the average human hair, nanofibres are used to create advanced wound dressings and for tissue regeneration, drug testing, stem cell therapies and the delivery of drugs directly to the site of infection.
They are also used to manufacture fuel cells, batteries, filters and light-emitting screens.
Currently, the most common nanofibre manufacturing technique, electrospinning, uses high-voltage electricity and specially designed equipment. Operators must have extensive training to use the equipment safely.
“In contrast to other nanofibre spinning devices, most of the equipment used in our device is very simple,” Minko said. “Essentially, all you need is a magnet, a syringe and a small motor.”
At laboratory scale, a very simple handcrafted set-up is capable of producing spools containing hundreds of yards of nanofibres in a matter of seconds.
Polymer that has been melted or liquefied in a solution is mixed with biocompatible iron oxide or another magnetic material and placed inside a hypodermic needle.
This needle is then positioned close to a magnet that is fixed atop a spinning circular platter. As the magnet passes by the tip of the needle, a droplet of the polymer fluid stretches out and attaches to the magnet, forming a nanofibre string that winds around the platter as it continues to spin.
The device can spin at more than 1,000 revolutions per minute, enough time to create more than 50km of ultra-thin nanofibre.
The process is relatively simple but produces a very high-quality product, said Alexander Tokarev, paper co-author and postdoctoral research associate in Minko’s lab.
“The product we can make is just as thin and just as strong as nanofibres created through other methods,” he said. “Plus, users don’t have to worry about the safety issues of using high voltages or the complexity of other machines.”
The researchers can use this method to create a variety of nanofibres by changing the polymer placed in the syringe. For example, they can create nanofibres that will promote the growth of stem cells. Fibres such as these are currently used to create scaffolding for lab-grown tissues and organs.
Nanofibres can also be loaded with proteins, nanotubes, fluorescent materials and therapeutic agents.
“We can use almost any kind of polymer with this platform, and we can tailor make the nanofibres for different applications,” Minko said.