Additive manufacturing — also referred to as 3D printing — has advanced past initial applications involving production of plastic prototypes for engineers and designers, with notable progress achieved in medical applications.

The advent of 3D printing offers a route to the design of smarter, sensor-equipped and patient-specific Schematic of the tissue engineering and 3D-printing process. Source: N. Noor et al.implants. The technology also supports the production of life-like anatomic forms as physical representations of a patient’s anatomy. Cardiac structures have been previously 3D printed, and now scientists have 3D printed a heart containing blood vessels, cells and chambers, using patients’ own biological material.

The study reported by Tel Aviv University, Israel, researchers in Advanced Science begins with the processing of fatty tissue biopsied from patients. Cells are reprogrammed to function as pluripotent stem cells while the extracellular matrix, a 3D assemblage of extracellular collagen, glycoproteins and other macromolecules, is processed into a personalized hydrogel for use as the biological ink.

Patient-specific, immune-compatible cardiac patches with blood vessels and, subsequently, an entire heart, were 3D printed with a hydrogel bio-ink/stem cell mixture. The resulting anatomically precise organ, about the size of a rabbit’s heart, is not yet ready for actual implantation. The heart’s cells were demonstrated to contract, but cardiac pumping capacity must be further improved in long‐term in vitro studies and in vivo implantation trials in animal models. The 3D-printing technology is expected to broaden approaches for organ replacement after failure, or for drug screening in specific anatomical structures.