A unique polymeric material disassembles when exposed to low levels of near-infrared irradiation and is well-tolerated by cells. The new "smart" polymer could be used for noninvasive medical and biological applications. Researchers at the University of California report that the polymeric materials — either synthetic or natural — are specifically designed to break down into small fragments in response to very low levels of NIR irradiation. The materials could be used for tissue engineering, implants, wound-healing, drug delivery and biosensors. NIR irradiation penetrates up to 10 cm deep into tissues with more precision and less damage, absorption and scattering than visible light produces. Though other materials respond to high-level NIR irradiation, they are difficult to clear from the body. Until now, none responded to safer, low-level NIR light, which causes less photo-damage to cells and tissues. The researchers are working on synthetic and engineering strategies to create bio-materials that are even more sensitive to NIR irradiation. "What we're doing now is to develop these materials for clinical application and as a biomedical research tool," said Dr. Adah Almutairi, assistant professor at the University of California, San Diego, Skaggs School of Pharmacy and Pharmaceutical Sciences. "The clinical application we've started working on is ocular delivery of therapeutics for macular degeneration; this material would serve as a depot that releases [a] drug upon gentle irradiation when dosage is needed." The group's work was published online Sept. 30 in Macromolecules (doi: 10.1021/ ma201850q).