title: Bone Tissue Regeneration - Application of Mesenchymal Stem Cells and Cellular and Molecular Mechanisms.
abstract: 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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: School of Dentistry, Shandong University, Jinan, Shandong 250012, China.|Key Laboratory of Oral Biomedicine, Shandong University, Jinan, Shandong 250012, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Division of Oral Biology, Tufts University School of Dental Medicine, Boston, MA 02111, United States.
authors.forename: Jake
authors.initials: J
authors.lastname: Chen
mesh_terms: D000818:Animals; D001861:Bone Regeneration; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000502:physiology*; D010006:Osteoblasts; D010010:Osteoclasts; D023822:Tissue Engineering / Q000379:methods*
keywords: Mesenchymal stem cells; bone regeneration; immunoregulation; osteoblast; osteoclast; tissue engineering