It sounds straight out of a comic book: Scientists have figured out a way to inject gene-carrying nanoparticles into stem cells in order to make wounds heal faster. I'd get my superheroine costume ready if the method wasn't potentially cancer-causing.

The basic idea is to use nanoparticles to deliver a gene into stem cells which will "encourage new blood vessels to grow so that the tissue stays alive." The results in mice certainly do sound encouraging:

When the modified cells were injected into mice whose hind limbs had been injured, the tissue that regrew to repair the damage had three times the blood vessel density of similar tissue in mice given unmodified cells. Four weeks later, only 20 per cent of the mice given modified cells had lost limbs, compared with 60 per cent in mice that received unmodified cells

The trouble with injecting modified cells like this is that the effects seem to drop off after a period of time. Scientists are looking for other methods, such as using a virus to transmit the gene, but "the viral approach is not without risks–viru