The tree · Replacing lost cells and parts
A printed or lab-grown organ works in a person for a year
Take a few of a person's own cells, grow them on a scaffold shaped like the organ, and put the result in. In 2006 a North Carolina group reported seven young people with bladders made this way, working for years. Nothing more complicated than a hollow organ has been done, and printed organs with their own blood supply remain in the laboratory. The leaf is written to count working organs, not patches: skin, cartilage and blood vessels grown from cells are already approved, but they replace a surface or a tube, not an organ's job.
What would count
An organ built outside the body from living cells, with or without a printed scaffold, is placed in a person and does that organ's job for at least a year, in a peer-reviewed report. Organ here means a bladder, kidney, liver, heart, lung, pancreas, windpipe, oesophagus or length of intestine; skin, cartilage, cornea and blood vessels are counted as tissues and left out. For the clinic rung: a regulator approves an engineered organ for use outside a trial.
Who settles it: Peer-reviewed reports with follow-up of a year or more; a regulator's approval record if an engineered organ is approved.
Where it stands
First human. Reached 15 April 2006, on the record of Atala and 4 others, 15 April 2006 (doi.org). Next rung within 5 to 20 years.
This is one of the 5 treatments shared with the sister site The Upgrade Tree, which keeps its own record of it at the same test and the same stage. The weekly reading checks that the two stages agree.
When it reaches the clinic: the project's estimate
This is the one thing on this page that is a judgment rather than a record. The project's estimate of the year it reaches the clinic is 2045, no earlier than 2032 and no later than 2100; the model draws from that range every run, with the likely year the most probable draw. Set 16 October 2026, a first pass awaiting an outside review.
| Rung | No earlier than | Most likely | No later than | |
|---|---|---|---|---|
| In clinical use | 2032 | 2045 | 2100 | feeds the year at the top |
Why. Twenty years after the bladders, no engineered organ is in a late-stage trial; the solid organs need a blood supply that nobody has grown at scale. The likely year assumes a hollow organ (a bladder or a length of windpipe or gut) reaches an approval in the mid 2040s through a rare condition; the earliest assumes one of the bladder programmes restarts and files on existing data; the latest allows for the vascular problem staying unsolved for the century.
Changes to this record
None since it was written on 16 October 2026. Every change to the stage or the estimate lands here with its date, the old value, the new one and the reason, and a change to the estimate never happens because a number looked wrong: it needs a dated reason and a source.
The last readings
- 17 October 2026 Quiet
Nothing in the window. The searches returned older trachea follow-ups (the 2008 case's five-year report, a 2012 paediatric case), a 2022 oesophagus study in piglets, a 2025-11 report of a 3D-printed corneal implant in a phase 1 trial at Rambam in Haifa (cornea is a tissue and left out by the test), and a 2026-01 ARPA-H grant of 28.5 million dollars to a Carnegie Mellon team to develop a printed liver, which is funding, not an organ in a person.
What the story so far says about it
On the record
Notes
The record is the 2006 Lancet report of engineered bladders in seven patients. The printed ear of 2022 (a company announcement with no peer-reviewed report) is cartilage, not an organ, and would not count under the test even if published. The later synthetic windpipe cases of the 2010s were found to be fraudulent and do not count. The Upgrade Tree keeps the same leaf at first human; the weekly reading checks the two stages agree.