Plug‐and‐Play Multimaterial Chaotic Printing/Bioprinting to Produce Radial and Axial Micropatterns in Hydrogel Filaments

Abstract

Nature abounds with micro‐architected materials containing layered multi‐material patterns that often transition within the very same monolithic piece. Fabricating these complex materials using current technologies is challenging. Multimaterial chaotic printing is presented—an extrusive printing method based on the use of chaotic advection—that can fabricate microstructured hydrogels with well‐defined multimaterial and multilayered micropatterns. Printheads containing internal Kenics static mixing (KSM) elements and top‐ and lateral‐positioned inlets are used to produce a wide repertoire of multilayered hydrogel filaments. In this plug‐and‐play system, the radial and axial micropatterns can be designed ad hoc by defining the printhead configuration (i.e., the number of KSM elements and inlets, and the inlet positions) and the flow program (i.e., activation/deactivation of the ink‐flow through each inlet). Computational fluid dynamics simulations closely predict the microstructure obtained by a given printhead configuration. The application of this platform is illustrated for easy fabrication of fibers with radial microgradients, bacterial ecosystems, structured emulsions, micro‐channeled hydrogel filaments, a pre‐vascularized tumor niche model, and skeletal muscle‐like tissues with axial and radial transitions of bioactive glass compartments. It is envisioned that multimaterial chaotic printing will be a valuable addition to the toolbox of additive manufacturing for the rational fabrication of advanced materials.

Sheet-based extrusion bioprinting: a new multi-material paradigm providing mid-extrusion micropatterning control for microvascular applications

“…Chaotic printing has been demonstrated as a viable strategy for inducing cell alignment, providing vacant channels for pre-vascularization and rapid cell expansion in high surface-area-to-volume bioreactor systems [24][25][26][27][28][29][30][31][32][33][34][35][36]. Chaotic printing has also recently been explored for producing radial and axial micropatterns with up to 8 inks at once [37].…”

Nozzle Innovations That Improve Capacity and Capabilities of Multimaterial Additive Manufacturing

“…This process is often called “vascularization” in the field of bioprinting. ,, Consequently, cell viability near the center of the filaments improved, as vascularization permits the transport of cell waste and growth media, which are necessary functions to maintain viability that are limited in tissues with thickness exceeding ≳100–200 μm . Recently, Kenics static mixers have been incorporated into more complex extrusion systems allowing several material feeds and variations along the filament length …”