Living three-dimensional micro fabricated constructs for the replacement of vital organ function

We report the first demonstration of high-resolution three-dimensional constructs of living tissue suitable for transplantation for vital organ replacement devices. This work invokes a microfluidic approach, in which the blood supply of the liver or kidney is simulated using computational fluid dynamics; the vascular supply is then fabricated by replica molding of thin sheets of biopolymers stacked to form three-dimensional channel networks. These vascular networks are lined with endothelial cells in capillary-like structures that permeate the polymer construct with a rich bed of blood vessels. Organ function is achieved by arranging organ-specific cells in compartments adjacent to the blood vessels, which are separated by nanoporous polymer membranes. Initial results demonstrate that rat hepatocytes are sustained and retain their function for periods of weeks when oxygenated medium is perfused through the engineered capillary networks, a promising first step towards the ultimate goal of organ replacement.