Paint out superbugs?

Biochemists at Manchester Metropolitan University believe hospital superbugs could be destroyed by painting surfaces with paint containing titanium dioxide nanoparticles, and then exposing those surfaces to fluorescent light.

The MMU team tested different formulations of the new paint under different types and intensities of light on the Escherichia coli (E. coli) bacteria.

They report that paints with higher concentrations of titanium dioxide nanoparticles were better able to kill bacteria and that ordinary fluorescent lights were sufficient to kill all E. coli.

Titanium dioxide is common in white paints and under UV light reacts with any water molecules on the particle surface to attack bacteria.

Now Lucia Caballero and colleagues in the Centre for Materials Science Research have set out to study whether white paint could be modified into a new weapon against hospital superbugs.

Caballero’s team began by exposing samples of E. Coli to paints containing no additives but high concentrations of titanium dioxide. They also experimented with paints lower in titanium dioxide, but with paint additives such as calcium carbonate.

In the course of those experiments, they found that the paint additives could block the killer properties of titanium dioxide.

‘If calcium carbonate was present, the ‘kill-rate’ dropped by up to 80 per cent,” said Caballero.

She thinks the additives block some titanium dioxide particles from becoming agitated by UV.

The results suggest paint could be made into a bacteria killer by adding more titanium dioxide and removing fillers.

But striking a balance between paint that is suitably deadly, but still long lasting, could prove difficult and Caballero said more research is required.