title: Stem cell-based therapies for osteoarthritis:  challenges and opportunities.
abstract: OBJECTIVE
  Regenerative medicine offers the exciting potential of developing alternatives to total joint replacement for treating osteoarthritis. In this article, we highlight recent work that addresses key challenges of stem cell-based therapies for osteoarthritis and provide examples of innovative ways in which stem cells can aid in the treatment of osteoarthritis.
  
  
  RESULTS
  Significant progress has been made in understanding the challenges to successful stem cell therapy, such as the effects of age or disease on stem cell properties, altered stem cell function due to an inflammatory joint environment and phenotypic instability in vivo. Novel scaffold designs have been shown to enhance the mechanical properties of tissue-engineered cartilage and have also improved the integration of newly formed tissue within the joint. Emerging strategies such as injecting stem cells directly into the joint, manipulating endogenous stem cells to enhance regenerative capacity and utilizing stem cells for drug discovery have expanded the potential uses of stem cells in treating osteoarthritis.
  
  
  CONCLUSIONS
  Several recent studies have greatly advanced the development and preclinical evaluation of potential stem cell-based treatments for osteoarthritis through novel approaches focused on cell therapy, tissue engineering and drug discovery.
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center and Duke University, Durham, North Carolina, 27710, USA.
authors.forename: Brian O
authors.initials: BO
authors.lastname: Diekman
authors.forename: Farshid
authors.initials: F
authors.lastname: Guilak
mesh_terms: D000375:Aging / Q000473:pathology; D004353:Drug Evaluation, Preclinical / Q000379:methods; D006801:Humans; D010003:Osteoarthritis / Q000473:pathology / Q000628:therapy*; D033581:Stem Cell Transplantation / Q000379:methods* / Q000639:trends; D013234:Stem Cells / Q000502:physiology; D023822:Tissue Engineering / Q000379:methods; D054457:Tissue Scaffolds