title: Human adipose derived stromal cells heal critical size mouse calvarial defects.
abstract: BACKGROUND
  Human adipose-derived stromal cells (hASCs) represent a multipotent cell stromal cell type with proven capacity to differentiate along an osteogenic lineage. This suggests that they may be used to heal defects of the craniofacial or appendicular skeleton. We sought to substantiate the use of undifferentiated hASCs in the regeneration of a non-healing mouse skeletal defect.
  
  
  RESULTS
  Human ASCs were harvested from female lipoaspirate. Critical-sized (4 mm) calvarial defects were created in the parietal bone of adult male nude mice. Defects were either left empty, treated with an apatite coated PLGA scaffold alone, or a scaffold with human ASCs. MicroCT scans were obtained at stratified time points post-injury. Histology, in situ hybridization, and histomorphometry were performed. Near complete healing was observed among hASC engrafted calvarial defects. This was in comparison to control groups that showed little healing (*P<0.01). Human ASCs once engrafted differentiate down an osteogenic lineage, determined by qRT-PCR and histological co-expression assays using GFP labeled cells. ASCs were shown to persist within a defect site for two weeks (shown by sex chromosome analysis and quantified using Luciferase+ ASCs). Finally, rBMP-2 was observed to increase hASC osteogenesis in vitro and osseous healing in vivo.
  
  
  CONCLUSIONS
  Human ASCs ossify critical sized mouse calvarial defects without the need for pre-differentiation. Recombinant differentiation factors such as BMP-2 may be used to supplement hASC mediated repair. Interestingly, ASC presence gradually dissipates from the calvarial defect site. This study supports the potential translation for ASC use in the treatment of human skeletal defects.
authors.affiliation: Hagey Pediatric Regenerative Research Laboratory, Plastic and Reconstructive Surgery Division, Department of Surgery, Stanford University School of Medicine, Stanford, California, USA.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Levi
authors.forename: Aaron W
authors.initials: AW
authors.lastname: James
authors.forename: Emily R
authors.initials: ER
authors.lastname: Nelson
authors.forename: Dean
authors.initials: D
authors.lastname: Vistnes
authors.forename: Benjamin
authors.initials: B
authors.lastname: Wu
authors.forename: Min
authors.initials: M
authors.lastname: Lee
authors.forename: Ankur
authors.initials: A
authors.lastname: Gupta
authors.forename: Michael T
authors.initials: MT
authors.lastname: Longaker
mesh_terms: D000273:Adipose Tissue / Q000166:cytology*; D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000502:physiology; D001842:Bone and Bones / Q000166:cytology; D002454:Cell Differentiation; D005260:Female; D006801:Humans; D017403:In Situ Hybridization; D008297:Male; D051379:Mice; D008819:Mice, Nude; D010012:Osteogenesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012886:Skull / Q000002:abnormalities*; D017154:Stromal Cells / Q000166:cytology*
chemical_list: C525719:Bmp2 protein, mouse; D055396:Bone Morphogenetic Protein 2