21 Jul 2006
Scientists in Canada develop a biodegradable fiber with optical, microfluidic and drug release properties.
Conventional needle-syringes could be on the way out if a "smart" hypodermic needle made from biocompatible optical fiber takes off. Developed by a team from Polytechnique de Montreal , Canada, the porous double-core device can perform both sensing and drug delivery roles.
What's more, the fiber is said to be easy to recycle thanks to its biodegradable properties, a useful feature when you consider that billions of needle-syringes are disposed of every year.
Made from commercially available cellulose butyrate, the fiber consists of a 150 µm diameter inner core surrounded by a 450 µm outer core. The inner core allows laser pulses to be delivered to the target, while the outer core can be used to collect reflected light for analysis.
"As with most polymers, transmission is good in the visible to near-infrared with multiple absorption peaks in the mid-infrared," Maksim Skorobogatiy of Polytechnique de Montreal's Complex Photonic Structures and Processes group told optics.org. "Preliminary data shows that side-scattering dominates transmission loss on the order of a fraction of a dB/cm." Assuming that all of the power loss goes directly into heating, Skorobogatiy believes that the fiber could have a power capacity of several watts.
According to the researchers, the fiber can be impregnated with pharmaceutical compounds for release during treatment and gaps within the microstructured device provide a pathway for transferring fluids.
The team uses hydroxypropyl cellulose powder to support the fiber's inner and outer cores. Because the melting point of the powder is higher than the melting point of the fiber, the particles retain their powder state during the 180 degC drawing process. The resulting internal support structure is said to be highly porous.
Skorobogatiy and his colleagues are now looking for partners in the bio-medical sector who would be interested in commercializing the technology with the option of sharing intellectual property as well as licensing.