A biomimetic folding paper co-culture system for analyzing cellular crosstalk in bone healing: Interactions of bone morphogenetic protein-2, Wnt family member 1, periostin, and platelet-derived growth factor subunit A between periosteum-derived progenitor cells and adipose-derived stem cells.

Bone defects, commonly associated with osteoporosis, result in fragile bones prone to fractures in both men and women. Osteoporotic fractures often lead to prolonged healing due to impaired cell differentiation. Understanding cellular crosstalk during bone regeneration is crucial for developing effective treatments. Periosteum-derived progenitor cells (PDPCs) and adipose-derived stem cells (ADSCs) play essential roles in bone formation because ADSCs secret key growth factors, such as bone morphogenetic protein-2, Wnt family member 1, Periostin, and platelet-derived growth factor subunit A, that promote osteogenesis. To investigate cellular interactions in bone healing process in the natural bone microenvironment, we developed a biomimetic folding paper co-culture system that mimics the inflamed three-dimensional bone structure. This system enables co-culture of PDPCs and ADSCs, allowing the study of their protein crosstalk and osteogenic potential. Moreover, neutralizing assays were conducted to inhibit specific cytokines and evaluate their influence on osteogenesis. Our findings confirm that ADSCs promote osteogenesis through their secreted growth factors that enhance the differentiation and activity of PDPCs. Disrupting these cellular interactions through cytokine inhibition led to a significant reduction in osteogenic potential. It was evidenced by decreased protein expression and gene activation associated with bone formation. This biomimetic folding paper co-culture system effectively mimics the natural bone microenvironment and provides a novel platform to study bone healing mechanisms. This approach may lead to the development of more effective treatments for bone fractures.