How matrix viscosity affects 3D osteocyte morphogenesis

During bone formation, osteoblasts are embedded in a collagen-rich osteoid tissue and differentiate into an extensive 3D osteocyte network throughout the mineralizing matrix. However, how these cells dynamically remodel the matrix and undergo 3D morphogenesis (development of shape) remains poorly understood. Although matrix stiffness has been the focus in mechanobiology, the role of matrix viscosity is often overlooked. Recently, Margherita Bernero - ETH ALIVE doctoral fellow in our lab, has developed a viscoelastic alginate–collagen interpenetrating network (IPN) hydrogel for 3D culture of murine osteocyte-like IDG-SW3 cells. Our findings reveal that fast stress-relaxing hydrogels enhance early osteocyte morphogenesis, while slow-relaxing hydrogels favor osteogenic differentiation after 14 days, highlighting their mechanosensitivity to matrix mechanics.

Interpenetrating network hydrogels for studying the role of matrix viscoelasticity in 3D osteocyte morphogenesis. Biomater. Sci., 2024, 12, 919-932 ( Margherita Bernero , Doris Zauchner , Ralph Mueller and Xiao-Hua Qin ). #Hydrogels #Bone #Osteocytes # Mechanobiology #Cell-matrix Interactions #Development #3R #Advanced Engineering with Living Materials (ALIVE) ETH Zurich Competence Center for Materials and Processes (MaP)

Link to animation for live-cell Ca2+ imaging: GFP-labelled osteocytes are lightening up in response to fluidic stimulation (2 Pa).