The artificial womb: What is the next step?

Recently the journal published the bold groundbreaking work of Joseph Church (et al.) [1,2]. It represents a major step forward in the care of premature neonates. However, as he noted, the utility of the technique will be severely limited as long as the devices require high dose heparin. While he hopes to create cannulas and an oxygenator without thrombogenic surfaces, this seems unlikely to succeed unless he is able to clone vascular endothelial cells. In that case, the cells suspended in their culture medium could be instilled into the devices and allowed to coat their surfaces.