The trend towards in vivo bioprinting

Bioprinting is one of several newly emerged tissue engineering strategies that hold great promise in alleviat-ing of organ shortage crisis. To date, a range of living biological constructs have already been fabricated in vitro using this technology. However, an in vitro approach may have several intrinsic limitations regarding its clinical applicability in some cases. A possible solution is in vivo bioprinting, in which the de novo tissues/organs are to be directly fabricated and positioned at the damaged site in the living body. This strategy would be particularly effective in the treatment of tissues/organs that can be safely arrested and immobilized during bioprinting. Proof-of-concept studies on in vivo bio-printing have been reported recently, on the basis of which this paper reviews the current state-of-the-art bioprinting technologies with a particular focus on their advantages and challenges for the in vivo application.