Opportunities and challenges of translational 3D bioprinting.

3D-printed orthopaedic devices and surgical tools, printed maxillofacial implants and other printed acellular devices have been used in patients. By contrast, bioprinted living cellular constructs face considerable translational challenges. In this Perspective, we first summarize the most recent developments in 3D bioprinting for clinical applications, with a focus on how 3D-printed cartilage, bone and skin can be designed for individual patients and fabricated using the patient's own cells. We then discuss key translational considerations, such as the need to ensure close integration of the living device with the patient's vascular network, the development of biocompatible bioinks and the challenges in deriving a physiologically relevant number of cells. Lastly, we outline untested regulatory pathways, as well as logistical challenges in material sourcing, manufacturing, standardization and transportation.