Biomimetic Materials for Bone Tissue Engineering - State of the Art and Future Trends

Bone tissue engineering is extremely promising for regenerating large bone defects in orthopedic or maxillofacial surgery. It consists of harvesting, culturing and differentiating human mesenchymal stem cells in combination with scaffolds. Different cell sources, such as bone marrow or adipose tissue, have been studied. Biomaterials resembling bone extracellular matrix have been used for scaffolding cells. However, these macroporous calcium phosphate ceramics or biodegradable polymers are two dimensional structures at the cellular level and have low osteogenesis properties in vivo. In this paper, several biomimetic approaches involving hydrogels or particles for 3-dimensional (3D) cell cultures are reviewed. High numbers of cells for low amounts of material induced abundant extracellular matrix formation in vitro and relatively large amounts of bone tissue formation in vivo. In addition, the 3D culture of several cell populations should make it easier for bone tissue constructs to vascularize, thus lifting the limits of current clinical applications.