Realizations of vascularized tissues: From platforms to grafts.

Vascularization is essential for realizing thick and functional tissue constructs that can be utilized for study platforms and grafts. The vasculature enables the transport of nutrients, oxygen, and wastes and is also indispensable to organ functional units such as the nephron filtration unit, the blood-air barrier, and the blood-brain barrier. This review aims to discuss the latest progress of organ-like vascularized constructs with specific functionalities and realizations even though they are not yet ready to be used as organ substitutes. First, the human vascular system is briefly introduced and related design considerations for engineering vascularized tissues are discussed. Second, up-to-date creation technologies for vascularized tissues are summarized and classified into the engineering and cellular self-assembly approaches. Third, recent applications ranging from tissue models, including generic vessel models, tumor models, and different human organ models such as heart, kidneys, liver, lungs, and brain, to prevascularized grafts for implantation and anastomosis are discussed in detail. The specific design considerations for the aforementioned applications are summarized and future perspectives regarding future clinical applications and commercialization are provided.