PODS® (Polyhedrin Delivery System) is an extensively tested and proven slow release protein formulation. The micron-scale protein co-crystals slowly release their cargo growth factors through nanopores, generating steady-state bioavailability (zero-order kinetics). This sustainable release enables precise control of the cell culture environment and generates near-constant growth factor concentrations, significantly improving the health and quality of cells. This slow-release reduces the number of media changes, which are traditionally required to replenish declining growth factor levels. This cycling between high and low growth factor concentration can stress cells (and researchers). But even more exciting, PODS nanocrystals can be precisely positioned to provide localized bioavailability and, if desired, micro-gradients. PODS are also highly stable in storage. This unparalleled flexibility and control of the system opens up many possibilities for innovation in 2D, 3D and in-vivo applications. Cells respond to spatial and temporal changes in growth factor availability. When using standard, soluble growth factors, there is little control over the position of a growth factor, which will spread evenly across the culture space. Standard growth factors also provide very little control over growth factor concentrations which diminish over time. The localized, sustained release capabilities of PODS allow spatiotemporal control of growth factor concentration. This enables a wide range of exciting applications including: Bioink functionalization • 3D culture • Organoids • Scaffolds • microfluidics (lab on a chip) • Improved and simplified stem cell culture • In-vivo survival agent for implanted cells • In-vivo and therapeutic protein delivery • Patterning and localization