(Nanowerk Spotlight) 3D bioprinting is an advanced additive manufacturing technique that attempts to recapitulate the native architecture of tissues through precise deposition of cell-containing hydrogel bioinks. The spatiotemporal control over bioink deposition allows for improved communication between cells and the hydrogel matrix, facilitating fabrication of anatomically and physiologically relevant structures.
Recent developments in hydrogel chemistries, reinforcement approaches, and crosslinking methods have expanded the applications of 3D bioprinting to pharmaceutics, regenerative medicine, and biomedical devices.
A multitude of 3D bioprinting techniques have been developed, but among these different approaches, extrusion-based 3D bioprinting has become a popular technique as it is easy to optimize and all its constituents are economical in price.
Despite the progress in extrusion based bioprinting in the last decade, the overall process of bioprinting can still be complex and challenging to scientists and researchers who are new to this field.
Extrusion-based 3D bioprinting is an emerging additive manufacturing approach for fabricating cell-laden tissue engineered constructs. (click on image to enlarge)
There are lot of people wanting to start research in bioprinting, but there are limited resources out there which actually cover the ABCs. Our review paper not only provides appropriate tools to the beginners in this field but also helps educate and navigate them to the current state-of-the-art approaches of 3D bioprinting, says Kaivalya Deo, graduate student in Gaharwar lab and the lead author of the project.
The review provides an overview of the 3D bioprinting process in discrete sections which guides the readers through the complete process and equips them with critical understanding of the steps needed to be taken before, during and after the bioprinting process.
Specifically, the authors explicate bioink design criteria, for extrusion-based 3D bioprinting techniques and the effects of various processing parameters on the biophysical and biochemical characteristics of bioinks. Furthermore, emerging trends and future directions in the area of bioinks and bioprinting are also highlighted.
The review discusses various biophysical and biochemical characteristics of bioinks and their relationship to the extrusion-based 3D bioprinting process. The bioink characteristics at different stages of the bioprinting process are highlighted.
In the initial sections the authors discuss the crucial bioink characteristics at pre-extrusion stage which include precursor viscosity, cell distribution, and biocompatibility.
Subsequently, the critical bioink attributes for extrusion are explained in detail, Specifically, the rheological properties of bioinks i.e. study of its flow behavior are discussed which determines printability, structural fidelity, and cell viability during the printing process. Lastly, considerations for post extrusion stage are expounded such as physiological stability and various characterization techniques of crosslinked 3D printed structures.
The article also talks about promising new research directions in the field of bioprinting. The authors indicate that the field is heading towards optimizing bioinks which not only provide cell viability and printability but also provide additional tunable functionalities, such as stimuli responsiveness and programmable properties. They discuss upcoming topics in bioprinting such as Multimaterial Bioprinting, 3D Printing Therapeutics, Bioprinting Tissue Models and 4D Bioprinting.
Provided by Texas A&M University as a Nanowerk exclusive