3D Bioprinting Using a Templated Porous Bioink

Abstract

3D cell printing (bioprinting) is rapidly emerging as a key biofabrication strategy for engineering tissue constructs with physiological form and complexity. [1][2][3][4] In practice, this process involves layer-by-layer deposition of a cell-laden bioink resulting in the additive manufacture of a patterned architecture with different cell types, growth factors, or mechanical cues, which are positioned with far greater precision than can be achieved with conventional scaffold-based tissue engineering. [ 5 ] While there have been signifi cant advances in printing technology, [ 6,7 ] progress has been limited by the rate of development of bioinks that are compatible with both 3D printing and tissue engineering. [ 8 ] These materials must be able to withstand extrusion, maintain structural fi delity for long time periods, and permit adequate nutrient diffusion, all under cytocompatible conditions. Due to their intrinsic porosity and capacity for high nutrient loading, hydrogels are the most promising candidate for bioink design, [ 9 ] particularly when gelation can be externally triggered using chemical bonding, [ 10 ] photoinduced crosslinking, [ 11 ] thermal setting, [ 12 ] or shear-thinning. [ 13 ] However, integrating these factors into a system while maintaining printability, structural persistence, and cell viability, is an enduring challenge. [ 14 ] Pluronic block copolymers of poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) present a possible pathway to print gelation, as they undergo a sol-gel transition upon heating near physiological temperatures. Here, elevating the temperature of these non-ionic surfactants reduces the

Mechanically Tunable Bioink for 3D Bioprinting of Human Cells

“…There has been extensive effort to build on and improve the properties of watersoluble polymers as bioinks. [15,16] For example, to overcome the limitation of the solubilization of Pluronic and its limited diversity of mechanical properties, blending of Pluronic with alginate [17] and crosslinking using acrylate-modified Pluronic have been explored. [10] Notwithstanding these advances that utilize chemical crosslinking to control the mechanical properties of the bioinks, controlling the shear behavior and mechanical This study introduces a thermogelling bioink based on carboxylated agarose (CA) for bioprinting of mechanically defined microenvironments mimicking natural tissues.…”

Digital biomanufacturing supporting vascularization in 3D bioprinting

“…Their specific design and formulation is becoming even more important as the industry is adopting such advances as multi-component bioinks in multi-step 3D printing process and anisotropic matrices [15] . Currently, researchers and printed construct sponsors in 3DBP must develop their own inks.…”

“…This will obviously demand a higher level of process monitoring, equipment integration, and process control. Co-deposition of two or more bioink streams can integrate desirable physical properties from each constituent component and exhibit complex phase behavior [15] . It is notable that both the effect of the matrix upon a cell type or implantation environment as well as the inclusion of high complements of cells upon the properties of the gel or matrix itself must be considered.…”

Technology: The promise of printing

“…This mix allows him to fine-tune the gelling time -Pluronic structures hold their shape well, but melt away too easily with changes in temperature, whereas alginate can gel too quickly. The mixed ink allows Perriman to print the structure he wants, then, once it's solidified, wash away the Pluronic, with the bonus that the gel leaves behind a network of micropores that allow the printed tissue to take up nutrients 3 .…”