The Promotional Effect of Mesenchymal Stem Cell Homing on Bone Tissue Regeneration

Background & Objective: Bone defects caused by bone fractures, malformations, postoperation on tumor and even periodontitis have became serious clinical problems. Although the exact origin of osteoblast precursors is still obscure, mesenchymal stem cells (MSCs) that originate from local bone marrow, periosteum, endosteum, mineralized bone or systemic circulation play key roles in osteoblastic differentiation and secretion of multiple factors during spontaneous healing of bone trauma or defect. Substantial evidences have shown that systemically infused MSCs can home and participate in bone tissue repair or regeneration. Applying pharmacological molecules to promote MSC homing or to mobilize MSCs in bone marrow niche to increase the amount of MSCs in the peripheral blood has been demonstrated to be important strategies to enhance MSC homing. However, there are some systemic conditions which influence MSC homing.In this paper, we review both systemic and local homing of MSCs during bone regeneration, and discuss strategies for enhancing the recruitment of MSCs to the injured bone tissues. Systemic influences of MSC homing are also discussed.