Developments of additive manufacturing and 5D printing in tissue engineering

Additive manufacturing, popularly known as “3D printing”, enables us to fabricate advanced scaffolds and cell-scaffold constructs for tissue engineering. 4D printing makes dynamic scaffolds for human tissue regeneration, while bioprinting involves living cells for constructing cell-laden structures. However, 3D/4D printing and bioprinting have limitations. This article provides an up-to-date review of 3D/4D printing and bioprinting in tissue engineering. Based on 3D/4D printing, 5D printing is conceptualized and explained. In 5D printing, information as the fifth dimension in addition to 3D space and time is embedded in printed structures and can be subsequently delivered, causing change/changes of the environment of 5D printed objects. Unlike 3D/4D printing that makes passive/inactive products, 5D printing produces active or intelligent products that interact with the environments and cause their positive changes. Finally, the application of 5D printing in tissue engineering is illustrated by our recent work. 3D/4D/5D printing and bioprinting are powerful manufacturing platforms for tissue engineering. Graphical abstract