Abstract

Extrusion Printing of Hydrogels with Embedded Cells

Paul Calvert, Professor of Bioengineering, UMass Dartmouth

A 3D printer has been used to make porous open gel "logpiles" with 200 micron bars containing embedded cells including yeast, fibroblasts and algae. The activity of the cells has been studied as a function of gel composition. As expected, cells can metabolize and multiply within a 100 microns of the gel surface. Following the activity of a yeast membrane-bound invertase and comparing this with known diffusion coefficients allows us to quantitatively model metabolism. The gel formulations need to give good strength coupled with easy diffusion of nutrients and products will be discussed. Diffusion coefficients have also been measured for a number of macromolecules in different types of printed gels in order to determine the possibility of using encapsulated cells in 3D gel scaffolds as small bioreactors to produce proteins.