3D bioprinting microgels to construct implantable vascular tissue.

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Engineered implantable tissues require robust, hierarchical vascular networks for nutrient transfer and mechanical stability under perfusion.
• Current 3D printing methods struggle to replicate complex vascular architectures, necessitating advanced bioink development.

Purpose of the Study:

• To develop a novel bioink capable of forming spontaneous hierarchical microvascular networks within 3D printed tissues.
• To enhance the mechanical properties of bioinks for implantable vascularized tissue engineering.
• To demonstrate the in vivo functionality of 3D printed vascularized tissues.

Main Methods:

• Utilized crosslinkable microgels within a soft gelatin methacryloyl (GelMA)-based bioink.
• Employed 3D printing to fabricate multi-branched tissue constructs.
• Incorporated human umbilical cord vein endothelial cells (HUVECs) to form microvascular networks.
• Performed direct surgical anastomosis of the 3D printed tissue between a rat carotid artery and jugular vein.

Main Results:

• The developed bioink enhanced mechanical stability of the 3D printed hydrogel tissues.
• Spontaneous formation of microvascular networks composed of HUVECs was observed within the printed constructs.
• Successful surgical implantation and vascular connection of the 3D printed tissue in a rat model were achieved.
• The engineered tissue demonstrated perfusion and integration with the host vasculature.

Conclusions:

• The novel bioink approach successfully creates mechanically stable, vascularized tissues with spontaneous microvascular network formation.
• This method represents a significant advancement in fabricating large vascularized tissues for potential organ failure treatments.
• The findings support the potential of this technology for future clinical applications in regenerative medicine.