Cartilaginous microtissues exhibit extreme resilience under compression with size-dependent mechanical properties

This study revealed how self-assembled cartilaginous microtissues derived from human periosteum-derived cells (hPDCs) exhibit exceptional mechanical resilience and size-dependent stiffness during large compressive deformations. Using strain-controlled tests, the authors showed that the Young’s modulus follows a power-law scaling with tissue diameter (E ∝ D^m) and increases with chondrogenic maturation. Microtissues sustained compressive strains exceeding 90 % without failure, exhibiting strain stiffening and stress relaxation with actomyosin-dependent oscillations. The findings highlight the importance of surface tension and tissue size in regulating the mechanical behavior of engineered tissues, informing the design of modular scaffold-free bone and cartilage regeneration therapies.