ananyo writes with this bit about lab grown organs from Nature
: "Scientists at Massachusetts General Hospital in Boston have fitted rats with kidneys that were grown in a lab from stripped-down kidney scaffolds. When transplanted, these 'bioengineered' organs starting filtering the rodents' blood and making urine. The team, led by organ-regeneration specialist Harald Ott, started with the kidneys of recently deceased rats and used detergent to strip away the cells, leaving behind the underlying scaffold of connective tissues such as the structural components of blood vessels. They then regenerated the organ by seeding this scaffold with two cell types: human umbilical-vein cells to line the blood vessels, and kidney cells from newborn rats to produce the other tissues that make up the organ (paper)."