3D bioprinting of architected hydrogels from entangled microstrands

Abstract

Hydrogels are an excellent biomimetic of the extracellular matrix and have found great use in tissue engineering. Nanoporous monolithic hydrogels have limited mass transport, restricting diffusion of key biomolecules. Structured microbead-hydrogels overcome some of these limitations, but suffer from lack of controlled anisotropy. Here we introduce a novel method for producing architected hydrogels based on entanglement of microstrands. The microstrands are mouldable and form a porous structure which is stable in water. Entangled microstrands are useable as bioinks for 3D bioprinting, where they align during the extrusion process. Cells co-printed with the microstrands show excellent viability and augmented matrix deposition resulting in a modulus increase from 2.7 kPa to 780.2 kPa after 6 weeks of culture. Entangled microstands are a new class of bioinks with unprecedented advantages in terms of scalability, material versatility, mass transport, showing foremost outstanding properties as a bioink for 3D printed tissue grafts.