I think, the scaffold is an extremely important part of the process, it has chemical and physical signals which allow stem cells to develop properly. I haven’t heard of a plastic scaffold being used except in Macchiarini scandal, where the patients either died or had to have their artificial windpipe replaced. And that was for a windpipe which is a layered 2D structure, not something like a lung with an enormously complicated 3D vasculature. I suspect artificial scaffolds will be far more difficult than the process covered here.

This is still ultimately a limitation not an impossibility. I can easily imagine some form of tissue deposition like 3D printing where you use laser activated gene regulation to control cell fate of the stem cells digitally at high spatial resolution.

From what I understand, artificial ECMs can be more difficult to build in some ways, but if you can figure out how to incorporate the right signaling factors into an artificial collagen matrix, you can avoid a lot of challenging biocompatibility/immune reaponse problems. Also, I believe most cells are differentiated before being seeded onto the scaffold.

Thanks for the information. I didn’t realize there were still biocompatibility issues even after the detergent process.

Your comment prompted me to find out about the Macchiarini scandal, which I had not previously been aware of. That's some seriously scary shit that went down there! When your experimental technique fails - again and again - and multiple people die - one after another - and you still go on doing it... that's just sick. Or dedication, I presume.

Macchiarini seems to have told lies about everything, not just his research. Strikingly, he told one journalist that he would marry her and the Pope himself would officiate (https://www.vanityfair.com/news/2016/01/celebrity-surgeon-nb...), while he in fact did not know the pope and also was already married.

The section about the bronchoscopy is this article is terrifying:

https://www.bbc.com/news/magazine-37311038

Stem cell science must above all avoid another Jesse Gelsinger case. Superstar researchers will always want to take chances, but the risks have to be strictly managed by the community or else there will be a backlash and progress will be set back by decades.