Self-assembled jawbone periosteal cell spheroids drive rapid osteogenic commitment through F-actin/NF-κB-mediated mechanotransduction

In contrast, direct activation in conventional monolayer cultures recapitulated the same gene expression program. Furthermore, spheroid formation induced significant disassembly of filamentous actin, and pharmacological stabilization of actin filaments downregulated both p65 phosphorylation and osteogenic gene expression. These findings establish a mechanotransduction axis whereby three-dimensional self-assembly triggers actin cytoskeletal remodeling, leading to NF-κB activation and subsequent osteogenic commitment.

Our work reveals that the physical event of cellular condensation intrinsically couples to an osteogenic priming program, providing new insights into how biophysical cues govern the early phases of bone formation, The jb-PDCs spheroid system established here also offers a unique platform for dissecting the mechanobiology of osteogenic initiation and may inform biomimetic strategies for craniofacial bone regeneration.