The blood substitute keeps the cells alive

The modified 3D printers, developed at Wake Forest, print human cells in hydrogel-based scaffolds.The lab-engineered organs are then placed on a 2in (5cm) chip and linked together with a circulating blood substitute, similar to the type used in trauma surgery.The blood substitute keeps the cells alive and can be used to introduce chemical or biologic agents, as well as potential therapies, into the system.Sensors which measure real-time temperature, oxygen levels, pH and other factors feed back information on how the organs react and crucially how they interact with each other.Dr Anthony Atala, institute director at Wake Forest and lead investigator on the project, said the technology would be used both to "predict the effects of chemical and biologic agents and to test the effectiveness of potential treatments". A group of experts from around the US is involved in putting together the technology, which will carry out toxicity testing and identification.The funding for the project was awarded by the Defense Threat Reduction Agency (DTRA), a division of the US government which combats nuclear, chemical and biological weapons.

The tests being carried out at Wake Forest "would significantly decrease the time and cost needed to develop medical countermeasures" for bioterrorism attacks, said Dr Clint Florence, acting branch chief of vaccines within the Translational Medical Division at DTRA.Wake Forest said it was able to test for antidotes to sarin gas, recently used against civilians in Syria.Dr Atala, whose field is regenerative medicine, said the bioprinting technology was first used at Wake Forest for building tissues and organs for replacement in patients.His team had managed to replicate flat organs, such as skin, tubular organs such as blood vessels, and even hollow non-tubular organs like the bladder and the stomach, which have more complex structures and functions.But building solid organs like the heart and the liver is the hardest challenge yet. The jet reached an altitude of 20,400 feet and an airspeed of about 288 miles per hour during today's flight, which tested the aircraft's systems and structures. Boeing said the jetliner's onboard equipment transmitted real-time data to the company's flight-test team in Seattle.