3D bio-screen printing for high-throughput production of scaffolds for meat alternatives

Increasing the production of structured cultivated meat (CM) remains a major challenge. Many current 3D printing and bioprinting technologies lack the necessary throughput, material compatibility, and cytocompatibility to produce realistic meat alternatives. In this study, screen printing, a traditional high-throughput printing technology, was investigated for the first time for the application of meat alternatives. The new process, 3D bio-screen printing (3D-BSP), presents a biomanufacturing process that uses edible materials (e.g., plant proteins) to produce meat-like structures with high resolution (0.1 mm). The suitability of edible inks for the 3D-BSP process was investigated on the basis of soy protein isolate (SPI) rheologically (flow index value < 0.4) and in terms of printability. In order to increase the protein content in edible inks while maintaining processability, an approach based on reducing agents was investigated. Sodium sulphite served as a demonstration model and resulted in a high protein content (>20 wt%) in SPI, while maintaining the flow properties suitable for processing protein-rich inks. To test the suitability as scaffolding technology for hybrid cultivated meat, meat-like scaffold structures were printed with C2C12 myoblasts differentiated on them. The printability of the structures was high in the resolution range investigated from 0.1 mm to 1 mm and supported 2D and 3D myoblast cultures (64% actin coverage and myotube formation). Ultimately, a marbled prototype was produced whose thickness could be increased by a stacking approach (>0.5cm). The texture profile (e.g., chewiness) of stacked and printed scaffolds was comparable to that of conventional meat. Upon successful transfer of the process parameters determined here to industrial screen printing machines, production rates of >100 kg/h could be achieved with one machine in the future. 3D-BSP offers a practical and cost-effective perspective for the mass production of structured meat in industrial quantities using screen printing technology. It could remove technical and economic barriers in this area and bring us closer to the commercial production of high-quality meat alternatives.