Burr-like, laser-made 3D microscaffolds for tissue spheroid encagement

This study describes the design, laser microfabrication, and validation of “burr-like” interlockable 3D microscaffolds (“lockyballs”) intended to encage tissue spheroids while preserving their ability to fuse with neighboring spheroids (a key requirement for bottom-up tissue self-assembly). The authors fabricated concentric, mechanically reinforced architectures via multiphoton polymerization of an organic–inorganic zirconium–silicate hybrid, modeled scaffold mechanics using finite element analysis, and experimentally compared compressive stiffness between open and concentric designs. They further demonstrated that preosteoblastic cells can be seeded into the microscaffolds with high viability (24–72 h), and that encaged spheroids retain fusion kinetics comparable to non-encaged spheroids, supporting the concept of combining scaffold-based reinforcement with spheroid-driven tissue assembly for in situ biofabrication.