Slashdot readers are technical people but are usually trained in the computer and engineering sciences. I'm a biochemist and I've been here since the beginning but I certainly do not come here for biological quality.
I perused the paper. It is in a good journal and it looks like some good work.
Single application question: how does phagocytosis of silicon nanowires differ in any significant way from good old run of the mill asbestos?
Answer: for those dreaming of a bioelectric interface I put forward that these silicon nanowires will cause cancer.
The authors do not address this and do not provide any experiment that would overcome this hurdle.
More specifically, you mean Mesothelioma and its relatives. Most cases are caused by asbestos, but only because we used it industrially and in our homes so widely. Broadly speaking, any sub-micron particles that (1) are anisotropic (sharp), and (2) that lack bio-solubility, will cause mesothelioma. The nano-particles act like little daggers that stay in your body forever, cutting back-and-forth as you move. Scar tissue builds up around them. Breathe, or in-take enough by other means, and it will happen. They're too small for the body to recognize as foreign, and are never ejected.
[CITATION: See work on nano-diamonds, immuno-gold, or III-V nano-particles. Cells do not spit them out like they do chemo drugs. . . which is why conjugating such particles with chemo drugs is such an attractive proposition.]
The list of materials that can do this goes on and on, but many are so rare that they're not reported. Talc, carbon, silicon carbide, olivine, and any number of exotic "new" materials that fit the above two criteria––all will cause mesothelioma, or a similar condition in other tissues.