3D Tissue and Organ Printing—Hope and Reality

Abstract

Three-dimensional (3D) bioprinting is an emerging, groundbreaking strategy in tissue engineering, allowing the fabrication of living constructs with an unprecedented degree of complexity and accuracy. While this technique greatly facilitates the structuring of native tissue-like architectures, many challenges still remain to be faced. In this review, the fruits of recent research that demonstrate how advanced bioprinting technologies, together with inspiring creativity, can be used to address these challenges are presented and discussed. Next, the future of the field is discussed, in terms of expected developments, as well as possible directions toward the realization of the vision of fully functional, engineered tissues, and organs. Last, a few hypothetical scenarios for the role 3D bioprinting may play in future tissue engineering are depicted, with an emphasis on its impact on tomorrow's regenerative medicine.

3D Printing of Physical Organ Models: Recent Developments and Challenges

“…[117] It is also a common strategy to construct vessel networks in 3D bioprinting by using fugitive/sacrificial materials. [204] From blood vessels to the whole heart, Dvir et al [211] also demonstrated the feasibility of personalized hydrogels to print heart with major blood vessels. Certainly, the conditions of 3D bioprinting are much more strict and complex than 3D printing organ models, which is not just adding cells into the printing process.…”

“…On the other hand, the future development of 3D printing organ models is not only closely related to the progress of 3D printing technology, but also goes hand in hand with the improvement of printing materials, design tools, process algorithms, and post‐processing techniques. [ 204 ] Furthermore, there is still a lack of a large number of randomized controlled trials to evaluate the effectiveness of organ models. [ 49 , 57 , 192 , 193 ] One of the reasons is that organ models are still difficult to be widely applied.…”

“…[ 117 ] It is also a common strategy to construct vessel networks in 3D bioprinting by using fugitive/sacrificial materials. [ 204 ] From blood vessels to the whole heart, Dvir et al. [ 211 ] also demonstrated the feasibility of personalized hydrogels to print heart with major blood vessels.…”

“…Certainly, the conditions of 3D bioprinting are much more strict and complex than 3D printing organ models, which is not just adding cells into the printing process. With that being said, we believe that the current challenges they face (such as the complexity of the fabricated structure, the accuracy of the printing, and the speed of the process) [ 204 ] and future directions can be discussed together. In the farther future, the innovation of 3D printing will constantly expand the potential of 3D bioprinting, and therefore the mutual enhancement of physical organ models and in vitro tissue models [ 212 , 213 ] will be more significant.…”

“…In the farther future, the innovation of 3D printing will constantly expand the potential of 3D bioprinting, and therefore the mutual enhancement of physical organ models and in vitro tissue models [ 212 , 213 ] will be more significant. 3D bioartificial organs [ 204 , 214 , 215 ] with complete organ functions will be the ultimate embodiment of the integration and development of these fields. Although there is still a long way to go, this is the inevitable pathway for organ models to go from “appearance resemblance” (having the same physical shape as real organs) to “spiritual resemblance” (having the same biological functions as real organs) that worth people making unremitting efforts.…”