Can scientists really 3D-print functional human organs?

The answer

Bioprinting has advanced rapidly from simple tissue scaffolds to functional mini-organs. In 2019, Tel Aviv University researchers 3D-printed a miniature heart using a patient's own cells, complete with blood vessels, ventricles, and chambers. By 2024, United Therapeutics' subsidiary 3D Systems successfully bioprinted human lung scaffolds seeded with living cells. Organovo has printed liver tissue patches undergoing clinical trials. The technology uses bio-inks - combinations of living cells, growth factors, and hydrogels - deposited layer by layer. A major breakthrough came in 2023 when researchers at the University of Minnesota printed functional heart muscle tissue that could actually beat. The primary challenges remain vascularization (creating the tiny blood vessel networks needed to nourish thick organs) and scaling printing speed, as current organs take hours to days to print.