3D Bioprinting of Macroporous Materials Based on Entangled Hydrogel Microstrands

ABSTRACT: Abstract Hydrogels are excellent mimetics of mammalian extracellular matrices and have found widespread use in tissue engineering. Nanoporosity of monolithic bulk hydrogels, however, limits mass transport of key biomolecules. Microgels used in 3D bioprinting achieve both custom shape and vastly improved permissivity to an array of cell functions, however spherical?microbead?based bioinks are challenging to upscale, are inherently isotropic, and require secondary crosslinking. Here, bioinks based on high?aspect?ratio hydrogel microstrands are introduced to overcome these limitations. Pre?crosslinked, bulk hydrogels are deconstructed into microstrands by sizing through a grid with apertures of 40–100 µm. The microstrands are moldable and form a porous, entangled structure, stable in aqueous medium without further crosslinking. Entangled microstrands have rheological properties characteristic of excellent bioinks for extrusion bioprinting. Furthermore, individual microstrands align during extrusion and facilitate the alignment of myotubes. Cells can be placed either inside or outside the hydrogel phase with >90% viability. Chondrocytes co?printed with the microstrands deposit abundant extracellular matrix, resulting in a modulus increase from 2.7 to 780.2 kPa after 6 weeks of culture. This powerful approach to deconstruct bulk hydrogels into advanced bioinks is both scalable and versatile, representing an important toolbox for 3D bioprinting of architected hydrogels. Bulk gels are deconstructed into hydrogel microstrands to form structured materials with interesting properties for tissue engineering. Preparation of this macroporous material is facile, cell?friendly, and material independent. Individual microstrands align through extrusion and facilitate orientation in biological structures. Entangled microstrands are an excellent bioink for extrusion 3D bioprinting and can be utilized as a platform for tissue engineering.

SUBMITTER: Kessel B 

PROVIDER: S-EPMC7509724 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature