Background & Objective: The regeneration of damaged bone tissues to a pre-disease state
has been a major goal for both clinicians and researchers worldwide. However, critical-sized bone defects
which are unable to heal completely are a major clinical concern because effective, evidencebased
regenerative therapy is still missing. Bone tissue engineering, aiming at providing novel and
effective materials to promote bone regeneration, has been considered as a promising alternative to the
traditional use of autografts, allografts and xenografts based on the fact that engineered bone tissue has
limitless supply and has no disease transmission. Mesenchymal stem cells (MSCs) can be derived from
various adult tissues such as adipose tissues, dental follicles of wisdom teeth, bone marrow, dental
pulp, gingiva, etc., which do not raise any ethical concerns. Furthermore, the application of MSCs in
bone tissue engineering has moved to the preclinical stage, and an ex vivo cell manufacturing procedure
for obtaining high quality, bioactive MSCs from human bone marrow has been approved by the US
Food and Drug Administration (FDA).
Summary: In this review, we summarized the cell sources and biological characteristics of MSCs, discussed
the in vivo functions of MSCs during bone regeneration, and briefly introduced the strategies for
the application of MSCs in bone tissue engineering. Further research efforts are still needed to facilitate
the application of MSCs in enhancing bone regeneration.