Gold Nanocomposite Bioink for Printing 3D Cardiac Constructs

Abstract

Bioprinting is the most convenient microfabrication method to create biomimetic three-dimensional (3D) cardiac tissue constructs, which can be used to regenerate damaged tissue and provide platforms for drug screening. However, existing bioinks, which are usually composed of polymeric biomaterials, are poorly conductive and delay efficient electrical coupling between adjacent cardiac cells. To solve this problem, we developed a gold nanorod (GNR) incorporated gelatin methacryloyl (GelMA)-based bioink for printing 3D functional cardiac tissue constructs. The GNR concentration was adjusted to create a proper microenvironment for the spreading and organization of cardiac cells. At optimized concentration of GNR, the nanocomposite bioink had a low viscosity, similar to pristine inks, which allowed for the easy integration of cells at high densities. As a result, rapid deposition of cell-laden fibers at a high resolution was possible, while reducing shear stress on the encapsulated cells. In the printed GNR constructs, cardiac cells showed improved cell adhesion and organization when compared to the constructs without GNRs. Furthermore, the incorporated GNRs bridged the electrically resistant pore walls of polymers, improved the cell-to-cell coupling, and promoted synchronized contraction of the bioprinted constructs. Given its advantageous properties, this gold nanocomposite bioink may find wide application in cardiac tissue engineering.

Collagen Hydrogel Containing Polyethylenimine‐Gold Nanoparticles for Drug Release and Enhanced Beating Properties of Engineered Cardiac Tissues

“…These data show that engineered cardiac tissues containing bPEI-AuNPs exhibit enhanced beating properties at 12 days post-fabrication. Notably, these data are in agreement with the literature showing enhanced contractility of these cells in the presence of AuNPs [21,22,33] and with our previous findings that elevated electrical conductivity results in cardiac tissues with enhanced contractile properties. [9][10][11]…”

Methacrylate‐Modified Gold Nanoparticles Enable Noninvasive Monitoring of Photocrosslinked Hydrogel Scaffolds

“…GelMA-Au hydrogels prepared by one-step photocrosslinking were shown to be cytocompatible with endothelial cells in 2D culture and were no less cytocompatible than gelMA alone in 3D culture. Previous studies investigating gelMA þ Au hydrogels reported either similar cell viability under similar conditions as this study, [54] enhanced cell activity at lower or similar concentrations of Au NPs, [36,37] and decreased cell viability at much lower concentrations of Au NPs. [38] Therefore, the safety of gelMA-Au hydrogels prepared by one-step photocrosslinking is promising but requires further investigation, including cytotoxicity in 3D culture and the in vivo toxicity, biodistribution, and clearance of released NPs.…”

Multifunctional Conductive Biomaterials as Promising Platforms for Cardiac Tissue Engineering

“…The results showed better cardiac cell adhesion and organization, a significantly higher protein level of Cx43, and significantly increased contraction rates due to the incorporation of AuNR into the bioprinted constructs (Figure B3–B5). AuNRs can connect cardiac cell bundles and enhance electrical propagation by creating conductive bridges across the matrices …”