In vitro fabrication of functional three-dimensional tissues with perfusable blood vessels

TLDR

Artificially engineered tissues hold therapeutic promise, yet creating complex, vascularized 3‑D tissues in vitro remains a longstanding challenge. The authors present a method to fabricate cardiac tissues with perfusable blood vessels in vitro. They employ a resected artery–vein vascular bed, overlay triple‑layer cardiac cell sheets from endothelial‑cell coculture, perfuse the construct in a bioreactor, and add extra layers to increase thickness. The resulting perfusable, beating cardiac tissue sheets survive transplantation, with endothelial cells forming tubular vessels, offering a new avenue for therapeutic tissue engineering.

Abstract

Artificially engineered tissues may have many therapeutic applications but complex tissues are hard to create in vitro. Here, Okano and colleagues report the production of functional cardiac tissue sheets with perfusable blood vessels, which increase the thickness and survival of transplanted tissue. In vitro fabrication of functional vascularized three-dimensional tissues has been a long-standing objective in the field of tissue engineering. Here we report a technique to engineer cardiac tissues with perfusable blood vessels in vitro. Using resected tissue with a connectable artery and vein as a vascular bed, we overlay triple-layer cardiac cell sheets produced from coculture with endothelial cells, and support the tissue construct with media perfused in a bioreactor. We show that endothelial cells connect to capillaries in the vascular bed and form tubular lumens, creating in vitro perfusable blood vessels in the cardiac cell sheets. Thicker engineered tissues can be produced in vitro by overlaying additional triple-layer cell sheets. The vascularized cardiac tissues beat and can be transplanted with blood vessel anastomoses. This technique may create new opportunities for in vitro tissue engineering and has potential therapeutic applications.