Scientists in the US have made an artificial cell that can locate sites of disease within the body.

Daniel Hammer and colleagues at the University of Pennsylvania, Philadelphia, and the University of Minnesota, Minneapolis, say they can engineer the cell to release its contents on cue, allowing it to deliver drugs directly to sites of disease. This approach could be useful in treating diseases such as cancer, they claim.

The artificial cells, known as leuko-polymersomes, are made from polymers that can self-assemble into vesicles that can be used for drug delivery. Polymersomes have been used in this way before but Hammer has now developed a way to make them behave like white blood cells. This lets them travel quickly and easily through blood vessels in the body.

The leuko-polymersome can encapsulate drugs and deliver them to the site of disease

'After the invention of polymersomes, it seemed natural to make an artificial white blood cell from them because there are so many ways that one can engineer the mechanical properties and release characteristics of polymersomes,' says Hammer.

Hammer and his team now plan to use different types of ligands on the polymersome's surface to target different locations within the body. 'These leuko-polymersomes are designed to travel to sites of inflammation,' explains Hammer. 'However, with different homing ligands, we envision developing particles that could find sites of cancer or other diseases.'

'The leuko-polymersome is a great example of biomimetics, and their tuneable strength and surface adhesion are proving useful for a range of clinical applications in drug delivery and medical imaging,' comments Michael King, an expert in biomedical engineering at the University of Rochester, US. 'Looking forward to the future, one could imagine the polymersome as an important building block in the field of synthetic biology, for instance incorporating ion channels to produce "smart" polymersomes which sense their surroundings, or encapsulating enzymatic cargo within circulating "micro-factories".'

Sarah Dixon