Clickable PEG-norbornene microgels support suspension bioprinting and microvascular assembly

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Developing perfusable, multiscale vascular networks is a major challenge in tissue engineering.
• Customizable and facile methods are needed for creating robustly vascularized tissue constructs.

Purpose of the Study:

• To engineer hierarchical vasculature using secondarily crosslinkable poly(ethylene glycol)-norbornene (PEGNB) microbeads.
• To evaluate PEGNB microbeads for supporting sequential suspension bioprinting and microvascular self-assembly.

Main Methods:

• Fabrication and characterization of clickable PEGNB microbeads.
• Suspension bioprinting of sacrificial bioinks within PEGNB microbead slurries.
• UV crosslinking of microbeads into granular constructs.
• Co-embedding endothelial and stromal cells for microvascular self-assembly.

Main Results:

• PEGNB microbead slurries supported suspension bioprinting and UV crosslinking.
• Sacrificial bioink evacuation and perfusion of patterned voids were successful.
• Co-embedded cells self-assembled into capillary-scale vasculature within the granular construct.
• Microvascular self-assembly was not affected by the bioprinting step.

Conclusions:

• Clickable PEGNB microbeads are versatile for suspension printing and microvascular culture.
• This methodology provides a foundation for engineering hierarchical vasculature.
• The combination of top-down and bottom-up approaches offers a novel strategy for tissue engineering.