“From Academia” features recent, relevant, close to commercialization academic publications in the space of healthcare 3D printing, 3D bioprinting, and related emerging technologies. In this issue, we included three recent publications all focusing on 3D bioprinting the heart. The first article is a review article overviewing recent progress on attempts to reconstruct the heart and heart tissues for various applications. The second is a now well-circulated paper from Adam Feinberg’s group on FRESH 3D bioprint a full-size heart. The final article showcase creative ways to scale bioprinting using multi-material projection-based stereolithography with a sacrificial bioink.
Authored by Chiara Gardin, Letizia Ferroni, Christian Latremouille, Juan Carlos Chachques, Dinko Mitrečić and Barbara Zavan, Cells. 17 March 2020
Three dimensional (3D) printing, which consists of the conversion of digital images into a 3D physical model, is a promising and versatile field that, over the last decade, has experienced rapid development in medicine. Cardiovascular medicine, in particular, is one of the fastest-growing areas for medical 3D printing.
In this review, we firstly describe the major steps and the most common technologies used in the 3D printing process, then we present current applications of 3D printing with relevance to the cardiovascular field. The technology is more frequently used for the creation of anatomical 3D models useful for teaching, training, and procedural planning of complex surgical cases, as well as for facilitating communication with patients and their families.
However, the most attractive and novel application of 3D printing in the last years is bioprinting, which holds the great potential to solve the ever-increasing crisis of organ shortage. In this review, we then present some of the 3D bioprinting strategies used for fabricating fully functional cardiovascular tissues, including myocardium, heart tissue patches, and heart valves.
The implications of 3D bioprinting in drug discovery, development, and delivery systems are also briefly discussed, in terms of in vitro cardiovascular drug toxicity. Finally, we describe some applications of 3D printing in the development and testing of cardiovascular medical devices, and the current regulatory frameworks that apply to the manufacturing and commercialization of 3D printed products.
Authored by Eman Mirdamadi, Joshua W. Tashman, Daniel J. Shiwarski, Rachelle N. Palchesko, and Adam W. Feinberg. ACS Biomaterials Science & Engineering, 23 October 2020
Recent advances in embedded three-dimensional (3D) bioprinting have expanded the design space for fabricating geometrically complex tissue scaffolds using hydrogels with mechanical properties comparable to native tissues and organs in the human body.
The advantage of approaches such as Freeform Reversible Embedding of Suspended Hydrogels (FRESH) printing is the ability to embed soft biomaterials in a thermoreversible support bath at sizes ranging from a few millimeters to centimeters. In this study, we were able to expand this printable size range by FRESH bioprinting a full-size model of an adult human heart from patient-derived magnetic resonance imaging (MRI) data sets.
We used alginate as the printing biomaterial to mimic the elastic modulus of cardiac tissue. In addition to achieving high print fidelity on a low-cost printer platform, FRESH-printed alginate proved to create mechanically tunable and suturable models. This demonstrates that large-scale 3D bioprinting of soft hydrogels is possible using FRESH and that cardiac tissue constructs can be produced with potential future applications in surgical training and planning.
Vascular bioprinting with enzymatically degradable bioinks via multi-material projection-based stereolithography
Authored by Alexander Thomas, Isabel Orellanoc, Tobias Lam, Benjamin Noichl, Michel-Andreas Geiger, Anna Klara Amler, Anna Elisabeth Kreuder, Christopher Palmer, Georg Duda, Roland Lauster, Lutz Kloke. Acta Biomaterialia. 24 September 2020
The introduction of cavities and channels into 3D bioprinted constructs is a prerequisite for recreating physiological tissue architectures and integrating vasculature. Projection-based stereolithography inherently offers high printing speed with high spatial resolution, but so far has been incapable of fabricating complex native tissue architectures with cellular and biomaterial diversity. The use of sacrificial photo inks, i.e. photopolymerizable biomaterials that can be removed after printing, theoretically allows for the creation of any construct geometry via a multi-material printing process. However, the realization of this strategy has been challenging because of difficult technical implementation and a lack of performant biomaterials. In this work, we use our projection-based, multi-material stereolithographic bioprinter, and an enzymatically degradable sacrificial photoink to overcome the current hurdles. Multiple, hyaluronic acid-based photoinks were screened for printability, mechanical properties and digestibility through hyaluronidase. A formulation meets all major requirements, i.e. desirable printing properties, generation of sufficiently strong hydrogels, as well as fast digestion rate, was identified. The biocompatibility of the material system was confirmed by the embedding of human umbilical vein endothelial cells with the followed enzymatic release. As a proof-of-concept, we bioprinted vascular models containing perfusable, endothelial cell-lined channels that remained stable for 28 days in culture. Our work establishes digestible sacrificial biomaterials as a new material strategy for 3D bioprinting of complex tissue models.