Tiny injectable particles containing protein 'factories' can be remotely activated by ultraviolet light. The technique could ultimately be used for drug delivery.

Credit: AM. CHEM. SOC.

Daniel Anderson and his group at the Massachusetts Institute of Technology in Cambridge created lipid spheres more than 100 nanometres in diameter that contained DNA and all the cellular ingredients and machinery needed to make proteins. By tagging the DNA with a chemical group that prevents it from being transcribed into RNA but can be removed using ultraviolet light, the researchers were able to control activation of RNA and protein production.

The authors developed nanoparticles that produce green fluorescent protein (pictured) and luciferase, an enzyme often used for in vivo molecular imaging. They showed that they could switch on luciferase production remotely after injecting the nanoparticles into mice.

Nano Lett. http://dx.doi.org/10.1021/nl2036047 (2012)