3D Printing Cell-Laden Living Materials

Microbes are extensively used in industry to convert carbon sources into valuable end-product chemicals and have found applications in the food industry, waste treatment, water quality assessment and bioremediation. Among them, species of two microalgal groups, diatoms and dinoflagellates, that exhibit appealing features for sensing devices were selected and encapsulated in hydrogels with different degrees of complexity to create 3D printed biohybrid materials with sensing behavior. We explore the encapsulation of such microorganisms within multifunctional hydrogels that supports the growth and proliferation of those non-mammalian cells by designing a set of ink and methods (direct ink writing-DIW or digital light processing-DLP) that allow to shape them in complex functional 3D structures. To accomplish our goals, we have first investigated the effect of the ink composition on the rheological behavior, printability, mechanical properties and cell growth in the hydrogels. The hydrogel inks were mainly composed of a suspension of microalgae (diatoms or dinoflagellates), polymers, water and nutrients. Next, we explored different printing methods to develop sensors to access water quality- and mechano-sensing hydrogels. The cell survival and activity upon encapsulation was confirmed and correlated to the mechanical properties of the hydrogels. We concluded that the proposed methods are promising for the design and fabrication of living materials with sensing properties such as water quality and force impact sensors.