Bioprinting of Decellularized Porcine Cardiac Tissue for Large-Scale Aortic Models

Abstract

Bioprinting is an emerging technique used to layer extrudable materials and cells into simple constructs to engineer tissue or arrive at in vitro organ models. Although many examples of bioprinted tissues exist, many lack the biochemical complexity found in the native extracellular matrix. Therefore, the resulting tissues may be less competent than native tissues—this can be especially problematic for tissues that need strong mechanical properties, such as cardiac or those found in the great vessels. Decellularization of native tissues combined with processing for bioprinting may improve the cellular environment for proliferation, biochemical signaling, and improved mechanical characteristics for better outcomes. Whole porcine hearts were decellularized using a series of detergents, followed by lyophilization and mechanical grinding in order to produce a fine powder. Temperature-controlled enzymatic digestion was done to allow for the resuspension of the decellularized extracellular matrix into a pre-gel solution. Using a commercial extrusion bioprinter with a temperature-controlled printhead, a 1:1 scale model of a human ascending aorta and dog bone shaped structures were printed into a reservoir of alginate and xanthium gum then allowed to crosslink at 37C. The bioengineered aortic construct was monitored for cell adhesion, survival, and proliferation through fluorescent microscopy. The dog bone structure was subjected to tensile mechanical testing in order to determine structural and mechanical patterns for comparison to native tissue structures. The stability of the engineered structure was maintained throughout the printing process, allowing for a final structure that upheld the dimensions of the original Computer-Aided Design model. The decellularized ECM (Ē = 920 kPa) exhibited almost three times greater elasticity than the porcine cardiac tissue (Ē = 330 kPa). Similarly, the porcine cardiac tissue displayed two times the deformation than that of the printed decellularized ECM. Cell proliferation and attachment were observed during the in vitro cell survivability assessment of human aortic smooth muscle cells within the extracellular matrix, along with no morphological abnormalities to the cell structure. These observations allow us to report the ability to bioprint mechanically stable, cell-laden structures that serve as a bridge in the current knowledge gap, which could lead to future work involving complex, large-scale tissue models.

Application of Acellular Dermal Matrix in Gynaecology—A Current Review

“…The procedure of removing cells from allogeneic human dermis results in a cell-free, non-immunogenic matrix composed of extracellular matrix (ECM) elements that can be re-inhabited by autologous cells. Such cell-free dermal matrices (ADMs) can also stimulate natural regenerative and reconstructive mechanisms [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ].…”

“…The women did not seek urogynological care from other doctors. To summarize, paravaginal reconstructions using the AlloDerm matrix turned out to be safe and well tolerated by the recipients [ 19 ].…”

“…Attention is drawn to the fact that there is a shortage of recent literature reports on the use of ADM in gynaecology. A large part of the analysed literature was published before 2015 [ 19 , 20 , 21 , 22 , 24 , 25 , 26 , 27 , 28 , 29 ]. Due to the proven effectiveness of the use of ADM in gynaecology, we encourage further research in this area.…”

Assessment of Angiogenesis and Cell Survivability of an Inkjet Bioprinted Biological Implant in an Animal Model

“…All samples were mounted using Cytoseal 60 (Thermo Scientific REF#8310-4). All procedures were taken from previously published protocols [24].…”

3D Inkjet-Bioprinted Lung-on-a-Chip

“…Bioprinting is a versatile technology that enables the automated fabrication of complex 3D-structured tissue models. , Computer-assisted deposition of cell-laden bioink enables the 3D fabrication of living tissues in a layer-by-layer manner, which allows high repeatability, reproducibility, and mass production by minimizing human intervention. , Among various bioprinting techniques, drop-on-demand inkjet bioprinting is capable of positioning living mammalian cells with micron resolution by ejecting a picolitre volume of the cell suspension, typically down to a single cell. , Inkjet offers the ability to construct thin and complex tissues layer-by-layer with different cell types by switching bioinks . The high-resolution patterning of living cells by inkjet has been demonstrated in 2D and 3D environments. , To date, bioprinting methods have been used for a wide range of tissues such as skin, , heart, bladder, , and lung. − Most of these studies have cultured bioprinted tissues under static conditions, so integrating with a microfluidic platform is a pivotal future step to mimic the in vivo environment by providing perfused culture conditions. Integrating inkjet bioprinting and the organ-on-a-chip platform has the synergistic potential to achieve a new generation of manufacturable in vitro models with structurally and physiologically more relevant 3D tissues in highly controlled cell–cell and cell-extracellular matrix communication interactions.…”