Hey gh56,
There is a graduate course on BioMEMs with Perez and it is very interesting where we read plenty of articles about the current practices. Yes I have been fascinated by 3D printing for a long time and I hope one day I can be a player in the field. Also Anthony Atala in Wakeforest has one of the leading institute in 3D bioprinting in the US followed by Melissa Little in Australia. There are plenty of hurdles in bioprinting organs though, besides the vasculature problem cellular organization has yet to be figured out. The scaffold, growth factors, environment cues, bioink I think are pretty easy at this point but putting them all together remains to be a challenge.