Scientists from the Oxford University have now developed a printer that can create tissues that have several properties of living tissue.

The type of material created by the printer has thousands of connected water droplets which are in a liquid film and act like living cells. The tissue doesn't resemble living tissue; rather, it mimics some of its properties.

Researchers say that the new material can be used in replacing damaged human tissue or to deliver drugs in the body. Also, since it has no genetic material, it can't make its own copies. This inability to replicate helps it avoid common problems associated with artificial tissue synthesis.

"We aren't trying to make materials that faithfully resemble tissues but rather structures that can carry out the functions of tissues.  We've shown that it is possible to create networks of tens of thousands connected droplets. The droplets can be printed with protein pores to form pathways through the network that mimic nerves and are able to transmit electrical signals from one side of a network to the other," said professor Hagan Bayley of Oxford University's Department of Chemistry, and one of the study authors.

The 3-D printer was created by Gabriel Villar, a DPhil student in Bayley's group. Villar is the lead author of the study.

A droplet made by the printer is 50 micron in diameter aqueous compartment. Each droplet is about five times bigger than a cell. However, researchers say that smaller-sized droplets could be made in the future.

"Conventional 3D printers aren't up to the job of creating these droplet networks, so we custom built one in our Oxford lab to do it. At the moment we've created networks of up to 35,000 droplets but the size of network we can make is really only limited by time and money. For our experiments we used two different types of droplet, but there's no reason why you couldn't use 50 or more different kinds," said Bayley in a news release.

The droplet networks made by the 3-D printers aren't just flat, but can be programmed to fold themselves. This ability to fold arises from the osmolarity differences that allow water transfer between cells.

The study is published in the journal Science.