Prevascularized

Prevascularized refers to engineered tissue constructs that contain a preformed vascular network or channels established in vitro prior to implantation. The aim is to accelerate perfusion after transplantation by enabling rapid anastomosis with the host circulation, thereby improving graft survival in large or thick tissues where diffusion alone is insufficient.

Common strategies include seeding endothelial cells together with supporting cells such as pericytes or mesenchymal stem cells on biocompatible scaffolds, and guiding the formation of capillary-like networks within hydrogels, decellularized matrices, or 3D-printed lattices. Microfluidic systems and bioprinting can create perfusable, hierarchical networks that mimic native vasculature. In some approaches, in vivo prevascularization uses implantation into a highly vascular site to promote vessel ingrowth before final transplantation.

Applications span bone, muscle, skin, adipose, liver, and islet transplantation, as well as other thick tissue constructs used in reconstructive surgery. Prevascularized grafts generally show faster perfusion, reduced ischemic necrosis, and improved functional integration compared with non-vascularized equivalents, particularly for defects exceeding the limits of simple diffusion.

Challenges include achieving consistent network maturity and stability, ensuring functional anastomosis with host vessels, scale-up and manufacturing, immune compatibility, and regulatory approval. Ongoing research focuses on standardizing protocols, improving perfusion dynamics, and translating promising preclinical results into clinical practice.