3D Printing of Functional Microalgal Silk Structures for Environmental Applications

Silk protein-based hydrogel materials suitable for hosting living microalgae due to the biocompatibility and ambient conditions gelation were developed. The silk was selected due to its robust mechanical properties, safe and compatible utility, green sourcing, and versatile materials formation. Through a series of assessments the mechanics and gelation kinetics of the hydrogel materials were optimized for three-dimensional (3D) printing. Silk hydrogel structures containing a marine microalgal strain, <i>Platymonas</i> sp. were printed and these structures supported cell proliferation for at least 4 weeks and consistent photosynthetic activity for more than 90 days, the limits of the study time frame. This long-term cell viability and function suggest that these systems may be suitable for a broad range of applications, such as oxygen replenishment and carbon dioxide reduction toward a green, healthier indoor environment.