Scaffold internal network bioprinting for vascularized tissue regeneration

Abstract

The regeneration of large-volume artificial organs necessitates effective vascularization. However, establishing free-form and perfusable vascular networks within these constructs remains a significant challenge. In this study, we introduce a novel printing technique termed Scaffold Internal Perfusable Vascular Network Printing (SINP), which utilizes microsphere suspensions to fabricate customizable vascular networks within a designated microsphere scaffold while simultaneously seeding multiple cell types for engineering vascularized tissues. This printing method offers three key advantages. Firstly, the GelMA microsphere bath promotes construct formation with substantial porosity, facilitating internal nutrient diffusion and cell infiltration. Secondly, the incorporation of sacrificial ink creates internal free-form channels that are essential for ensuring adequate nutrient supply in large-volume tissue scaffolds. Lastly, by seeding multiple cell types from the lumen of the tubes, including vascular endothelial cells, it is possible to construct specific vascularized tissues in vitro. Ultimately, we successfully printed centimeter-level demo-shaped vascularized breast tissue and demonstrated its regenerative efficacy in vivo and in vitro experiments, highlighting the potential of this innovative printing approach for regenerating large-volume vascularized tissues.