3D printing skin, bone, and even working organs could change transplant medicine and medical research — but how, exactly, does one “print” a heart or liver?

Engineers can now print three-dimensional replicas of a human heart custom-designed to look and act like an individual patient’s heart. The goal is to provide realistic models so that doctors ...

Miniature-sized heart chambers called ventricles have been 3D printed with live human heart muscle cells and shown to beat on their own for at least three months.