Polymer nanofibres can be sprayed onto surgical incisions, sealing them to prevent infection. The process may be used in addition to sutures, but may also remove the need for them in some cases.
The potential of mats of polymer nanofibers has been recognized for some time. They can seal up wounds, biodegrade so they don't need to be removed, and be impregnated with slow release drugs. Nanofiber mats also have potential as scaffolds on which to grow tissue from stem cells. The hitch, however, has been how to produce the mats in or on the human body without doing damage in the process.
Mats can be made through electrospinning where fine fibers are drawn from a liquid with an electric field, but the University of Maryland's Professor Peter Kofinas notes this “requires specialized equipment, high voltages and electrically conductive targets”. Cells can be damaged by the electric current. Kofinas used an airbrush, available from hardware stores, to apply paint to spray the nanofibers on, creating a mat that fits the surface to which it is applied.
To idea itself is not new. Kofinas had to experiment with different versions of poly(lactic-co-glycolic acid) (PLGA) to find one with the right molecular weight to work in the airbrush and still produce fibers with the 370nm diameter they found to be ideal.
Macro Letters reports the mats capacity to seal not only cuts to the skin, but also the lungs, intestines and livers of pigs. Kofinas used acetone, (CH3)2CO most familiar to non-scientists as nail polish remover, as a the solvent. Although acetone is highly flammable, and can irritate the eyes it is considered safe as a food additive. The body produces it naturally and diets that increase its levels are even used to reduce certain forms of epilepsy, although excesses can also occur as a result of alcoholism or diabetes. Kofinas found most evaporated and cells sprayed with the nanofibers showed no consequences from either the PLGA or the acetone.
The researchers believe the technique could be particularly applicable to hernias where, “Treatment frequently uses preformed polymer mats with a high incidence of recurrent herniation and bowel obstruction.”
A technique using a related concept, aerosol delivery of skin cells to burn victims, is under clinical trial.