Is extracellular matrix (ECM) a promising scaffold biomaterial for bone repair?

The increasing demand for bone grafts and the scarcity of donors worldwide are promoting researchers to seek alternatives. The extracellular matrix (ECM) has been reported to enhance properties of osteoconduction and osteoinduction by simulating the molecular structure of bone and facilitating cell infiltration for bone repair. As one of several novel biomaterials, ECM has many desirable properties, including biocompatibility, bioactivity, and biosafety. Thus, we evaluated whether ECM is a promising scaffold biomaterial for bone repair. In this review, we explore ECM composition, the sources and fabrication methods, especially the decellularization technique, of ECM scaffolds. Furthermore, we highlight recent progress in the use of ECM as a scaffold biomaterial for bone repair. Generally, ECM is used in 1) three-dimensional (3D) cell cultures to promote osteogenic differentiation, 2) combinations with other biomaterials to increase their osteogenic effects, 3) 3D printing to produce customized or patient-tailored scaffolds for bone repair, and 4) hydrogels derived from ECM used for bone repair. In addition, we focus on future prospects for application of ECM as a scaffold material used for bone repair. From this review, we expect to have a perfect understanding of ECM-based scaffold materials in the hope that this leads to further research of the production of ECM biomaterials to meet the clinical needs for bone repair.