“Silicon nanowires develop a uniform synthetic bone coating under an electric-field bias in simulated body fluid,” researcher Jeff Coffer told nanotechweb.org. “The hydroxyapatite-coated nanowires support fibroblast attachment and proliferation, and remain responsive to electrical bias even after coating, providing a system for electric-field modulated tissue regeneration.”

Coffer believes that this has two advantages. “First, the notion of electrical bias manipulation of possible biological function adds a desired level of control to any synthetic biomaterial,” he said. “Second, silicon does not demonstrate the cytotoxic concerns that carbon nanotubes and II-VI nanocrystals such as cadmium selenide (CdSe) express.”

The researchers believe the technique could have applications in situations of non-union bone growth - i.e. where a gap between two pieces of broken bone is not healing. “Accelerated calcium-phosphate deposition, brought about by the semiconducting nanowire, could facilitate the healing process and at the same time retain an active sensing element in the implant during tissue restoration,” said Coffer.

Now the team is interested in understanding how the surface chemistry of the nanowire affects its biological response “especially geared toward primary cell lines relevant to orthopaedics”. The researchers also plan to evaluate the properties of silicon nanowire-biopolymer composites.

The researchers reported their work in Advanced Materials.