Tissue model shows cells grown at the top of biodegradable scaffold consume nutrients first

The goal of tissue engineering is to create human tissue in the lab, circumventing the need for donor tissue that can be difficult to find or could be rejected by the host. However, cell growth depends on nutrients and the environment. Testing these factors can be expensive and take weeks.

Zong et al. developed a mathematical model to describe and optimize tissue growth on a scaffold of porous, biodegradable material. In each pore, human cells grow along the walls. Nutrients pass through the channel and are absorbed by cells, which then proliferate.

The team’s model takes just seconds to simulate tissue growth. It can be run in reverse to find the optimal geometry of the channels, a rounded square cross section and funnel-like structure.

They were the first to examine the impacts of cell hunger on cell growth.

“If you have a channel, the nutrient is flowing in from the top to the bottom. We wanted to know what happens if the cells on top are very hungry, and they eat a lot and don’t let food pass along for cells on the bottom,” said lead author Pejman Sanaei. “We found that this nutrient depletion is very important.”

Large hunger rates delayed growth for the bottom cells. If experimentalists can pin down the exact hunger rate, this model can be used to optimize tissue growth.

The researchers plan to study many other aspects of cell growth, like nonuniform scaffold geometries, imperfections in pores that disrupt nutrient flow, and elasticity of pore materials.

Source: “Effects of nutrient depletion on tissue growth in a tissue engineering scaffold pore,” by Zeshun Zong, Xinyu Li, and Pejman Sanaei, Physics of Fluids (2021). The article can be accessed at https://doi.org/10.1063/5.0071171 .