Direct 3D bioprinting of prevascularized tissue constructs with complex microarchitecture

Abstract

Living tissues rely heavily on vascular networks to transport nutrients, oxygen and metabolic waste. However, there still remains a need for a simple and efficient approach to engineer vascularized tissues. Here, we created prevascularized tissues with complex three-dimensional (3D) microarchitectures using a rapid bioprinting method – microscale continuous optical bioprinting (μCOB). Multiple cell types mimicking the native vascular cell composition were encapsulated directly into hydrogels with precisely controlled distribution without the need of sacrificial materials or perfusion. With regionally controlled biomaterial properties the endothelial cells formed lumen-like structures spontaneously in vitro. In vivo implantation demonstrated the survival and progressive formation of the endothelial network in the prevascularized tissue. Anastomosis between the bioprinted endothelial network and host circulation was observed with functional blood vessels featuring red blood cells. With the superior bioprinting speed, flexibility and scalability, this new prevascularization approach can be broadly applicable to the engineering and translation of various functional tissues.

A Facile Strategy for Fabricating Tissue Engineering Scaffolds with Sophisticated Prevascularized Networks for Bulk Tissue Regeneration

“…The vascular structure in tissues is hierarchical and resembles tree branches . Thus, the multi‐level bifurcation morphology and spatial degree have already exceeded those of a lot of previous research of hydrogel vascularization scaffolds . In addition, the compressive strength values of four different branch spatial gelation scaffold samples were 1.433, 1.421, 1.389, and 1.409 MPa (Figure ), respectively.…”

Microfluidic Bioprinting for Engineering Vascularized Tissues and Organoids

“…Therefore, nutrients and oxygen are still provided mainly through the interstitial space in the bioprinted scaffolds. The adaptation of sacrificial materials as the photocrosslinkable component of the bioink 64 may solve this issue in future versions of the technology. Alternatively, bioprinted hollow microfibrous structures 42,43,65,66,67,68 may be used as the vascular bed to ensure direct perfusion of the vascularized tissue constructs.…”

Multicellular Vascularized Engineered Tissues through User‐Programmable Biomaterial Photodegradation

“…[5] Additive techniques generate vascular constructs from the bottom up, either through stacking of 2D constructs [6] or layer-by-layer 3D printing, [7–9] where void spaces intentionally left during manufacturing define construct vascularity. Though these approaches have proven successful in generating perfusable vessels of varying geometry, studying endothelial cell function, [10] and modeling vascular pathology, [11] limited 3D control has been afforded.…”