3D Multicellular Scaffold Based Model for Advancing Bone Disorder Research

With growing life expectancy, skeletal research becomes increasingly important. Skeletal pathologies arise from a combination of age-related deterioration and disruptions in genetic, nutritional, or hormonal regulation of bone homeostasis. Bone research heavily relies upon 2D cultures or animal models. Tissue engineering has made progress in creating 3D models; however, most still lack cellular complexity, vascularization, and tissue maturity essential for mimicking native bone. This work presents composite multicellular 3D models, which include osteoblasts (that differentiate into osteocytes), osteoclasts, and endothelial cells, cultured on a biocompatible and biodegradable scaffold, enabling coordinated bone formation, resorption, and vascularization under controlled conditions. These tissue constructs exhibit hallmark features of bone mineralization, microvessel formation, and Tartrate Resistant Acid Phosphatase (TRAP)-positive osteoclast activity, as validated by histological, molecular, and functional assays. We applied the system to osteogenesis imperfecta, revealing pathophysiological phenotypes such as reduced Collagen Type I Alpha 1 Chain (COL1A1) expression and excessive matrix mineralization. This model overcomes key limitations of 2D cultures and animal models by enabling direct examination of dynamic cell–cell and cell–matrix interactions in a human-relevant context. By reproducing the spatial and functional organization of native bone tissue, the 3D multicellular bone model provides a robust and scalable system for investigating bone physiology, modeling disease, and screening therapeutic interventions.