Author:
Zhu Jinchang,He Yi,Wang Yong,Cai Li-Heng
Abstract
AbstractAnalogous of pixels to two-dimensional pictures, voxels –– in the form of either small cubes or spheres –– are the basic building blocks of three-dimensional (3D) objects. However, precise manipulation of viscoelastic bio-ink voxels in 3D space represents a grand challenge in both soft matter science and biomanufacturing. Here, we present a voxelated bioprinting technology that enables the digital assembly of interpenetrating alginate and polyacrylamide (PAM) double-network (DN) hydrogel droplets. The hydrogel is crosslinked via additive-free bioorthogonal chemistry involving a pair of stoichiometrically matched polymers. We develop theoretical frameworks to describe the crosslinking kinetics and stiffness of the hydrogels, and construct a diagram-of-state to delineate their mechanical properties. Multi-channel print nozzles are developed to allow on-demand mixing of highly viscoelastic bio-inks without significantly impairing cell viability. Further, we showcase the distinctive capability of voxelated bioprinting by creating highly complex 3D structures such as a hollow sphere composed of interconnected yet distinguishable hydrogel particles. Finally, we validate the cytocompatibility andin vivostability of the printed DN scaffolds through cell encapsulation and animal transplantation.
Publisher
Cold Spring Harbor Laboratory