Boston: Scientists in the US are a closer to creating artificial blood vessels after growing tiny tubes out of stem cells.

The Massachusetts Institute of Technology team were able to create cells that formed tubes along a grooved template.

Now they plan to produce capillaries which could be tested in animals, according to a report in the magazine Advanced Materials.

Researchers have already managed to make larger blood vessels , but the creation of tiny capillaries is far more difficult.

The US scientists claim to have made progress towards this, using a “nanoscale” template into which stem cells called endothelial progenitor cells are placed.

The cells detected the grooves and elongated themselves along them, aligning themselves in the same direction.

Adding a gel made of growth factors allowed the cells to grow outwards, forming a series of tiny tubes running parallel to each other.

While these tubes are not yet ready to be put inside a human body, the researchers say they are “very excited” by their potential.

The research was led by Professor Robert Langer, who said: “It provides a new way to create nano-based systems which we hope will provide a novel way to some day engineer tissues in the human body.”

The team now plan to develop capillary tubes which can be inserted into animals to see if they work properly.

The technology may also have other uses such as preventing unwanted growth in cancer and tumours.