A novel high-speed production process to create modular components for the bottom-up assembly of large-scale tissue-engineered constructs

Abstract

To replace damaged or diseased tissues, large tissue-engineered constructs can be prepared by assembling modular components in a bottom-up approach. However, a high-speed method is needed to produce sufficient numbers of these modules for full-sized tissue substitutes. To this end, a novel production technique is devised, combining air shearing and a plug flow reactor-style design to rapidly produce large quantities of hydrogel-based (here type I collagen) cylindrical modular components with tunable diameters and length. Using this technique, modules containing NIH 3T3 cells show greater than 95% viability while endothelial cell surface attachment and confluent monolayer formation are demonstrated. Additionally, the rapidly produced modules are used to assemble large tissue constructs (>1 cm(3) ) in vitro. Module building blocks containing luciferase-expressing L929 cells are packed in full size adult rat-liver-shaped bioreactors and perfused with cell medium, to demonstrate the capacity to build organ-shaped constructs; bioluminescence demonstrates sustained viability over 3 d. Cardiomyocyte-embedded modules are also used to assemble electrically stimulatable contractile tissue.

Keywords: bioreactors; cardiomyocytes; endothelial cells; scale-up; vasculature.