Tian and his colleagues created a nanowire-coated joint and placed it in mice. After four weeks, the researchers found that tissue had adhered to the joint. "We saw beautiful tissue growth - lots of muscle fibers," Tian said. "We've added one more function to the currently-in-use titanium implant."
Because the researchers can control the size and shape of the pores in the nanowire scaffold, the material also could be coated onto stents used in patients with coronary artery disease and in potential stroke victims. Conventional stents sometimes become reclogged with fat after implantation.
The most recent stent used to address this problem, called the drug-eluting stent, consists of a polymer coating mixed with the drugs, but the coating may be vulnerable to biodegradation, and may not function for long.
The nanowire coating without the degradation problem could be used to carry drugs that would help keep the arteries clear over a long period of time. "This drug release could be applied to the angioplasty catheter's surface," Tian said.
In addition to these biomedical applications, the nanofiber scaffold has a property that may make it useful in both hospitals and food processing plants: The material, when rinsed in water and exposed to ultraviolet light, kills more than 99 percent of bacteria on its surface.
This effect occurs because photons from the light cause a charge separation on the material, splitting water molecules into free radicals that destroy the bacteria. Alternatively, immersion in 70 percent ethanol completely sterilizes the material, allowing growth of cells/tissues in the laboratory prior to implantation.
This property could prove extremely useful in bacteria-prone environments, performing such functions as sterilizing on-site surgery hospitals used during military actions or cleaning surfaces in meat-processing plants.
"You could just use water to rinse and UV light to sterilize surfaces," Tian said. The researchers have applied for a provisional patent for the multifunctional nanowire bioscaffolds on titanium or titanium-containing alloys such as Nitinol.
marketing@alchempro.com
