Microfiber-shaped building blocks assemble to form liver cell tissue with blood vessel networks
Microfiber-shaped building blocks assemble to form liver cell tissue with blood vessel networks lead image
New advances in regenerative medicine continue to increase demand for functional three-dimensional tissue scaffolds on which to hold cells that make up regrown tissues. Focus in designing such tissue structures has recently shifted from a top-down engineering approach to a bottom-up one, in which larger tissues are made from assembling microscale ones.
Kurashina et al. present new microfiber-shaped tissue building blocks that can be assembled into larger tissues. Using a double coaxial microfluidic device, the group constructed two types of tissue that housed liver cells fed by a network of blood vessels constructed with human umbilical vein endothelial cells.
The group created the microfiber tissues by encapsulating liver cells in a calcium alginate shell. These are then strung together to form the tissue scaffolding and the shell is enzymatically removed.
They assembled a tissue with parallel scaffolding structure and one that could be reeled around a glass tube.
The samples produced in the study are among the earliest ones to contain vessel-lining endothelial cells for the growth of embedded vascular networks. This marks the first time such a tissue assembled with fiber-shaped building blocks has been grown with metabolically complex liver cells.
Author Hiroaki Onoe said the approach would be useful for many different applications that require three-dimensional cultures to handle large amounts of cells. Next, he said the group hopes to expand on the tissues for eventual use in patients.
“In this paper, we have not succeeded in infusing culture medium to the formed endothelial network in the assembled macroscopic tissue,” he said. “As with living organisms, the next challenge is to introduce liquid flow.”
Source: “Microfiber-shaped building-block tissues with endothelial networks for constructing macroscopic tissue assembly,” by Yuta Kurashina, Ryo Sato, and Hiroaki Onoe, APL Bioengineering (2019). The article can be accessed at https://doi.org/10.1063/1.5109966 .
