title: Evaluation of early healing events around mesenchymal stem cell-seeded collagen-glycosaminoglycan scaffold. An experimental study in Wistar rats.
abstract: OBJECTIVE
  Tissue engineering using cell-seeded biodegradable scaffolds offers a new bone regenerative approach that might circumvent many of the limitations of current therapeutic modalities. The aim of this experiment was to study the early healing events around mesenchymal stem cell-seeded collagen-glycosaminoglycan scaffolds.
  
  
  METHODS
  The 5-mm critical size defects were created in the calvarial bones of 41 Wistar rats. The defects were either left empty to serve as controls (n = 11), filled with cell-free scaffolds (n = 12), cell-seeded scaffolds that were maintained in standard culture medium (n = 9), or cell-seeded scaffolds that were maintained in osteoinductive factor-supplemented medium (n = 9). The animals were sacrificed at 7 days after surgery, and specimens were prepared for histological analysis. Early healing events such as host cell penetration, blood vessel in-growth, and scaffold integration were observed. The degree of inflammatory cell infiltrate was assessed.
  
  
  RESULTS
  While defects in the control group healed with a thin fibrous tissue, the collagen-glycosaminoglycan scaffold in the test groups preserved the three-dimensional form of the defects. After 7 days in vivo, the scaffold maintained its integrity and appeared populated with host cells. The cell-seeded scaffold induced more inflammatory response compared to the cell-free scaffolds. New blood vessels and areas of early bone formation were also evident in the cell-seeded scaffolds.
  
  
  CONCLUSIONS
  In conclusion, the findings show that mesenchymal stem cell-seeded collagen-glycosaminoglycan scaffolds have good tissue tolerance and exhibit an osteoinductive effect as indicated by early stage healing.
authors.affiliation: School of Dental Science, Trinity College, Dublin, Ireland. alhagm@tcd.ie
authors.forename: Mohamed
authors.initials: M
authors.lastname: Alhag
authors.forename: Eric
authors.initials: E
authors.lastname: Farrell
authors.forename: Mary
authors.initials: M
authors.lastname: Toner
authors.forename: Noel
authors.initials: N
authors.lastname: Claffey
authors.forename: T Clive
authors.initials: TC
authors.lastname: Lee
authors.forename: Fergal
authors.initials: F
authors.lastname: O'Brien
mesh_terms: D000818:Animals; D001861:Bone Regeneration / Q000502:physiology*; D003094:Collagen; D005549:Foreign-Body Reaction / Q000473:pathology; D006025:Glycosaminoglycans; D008297:Male; D045164:Mesenchymal Stem Cell Transplantation; D018919:Neovascularization, Physiologic / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012886:Skull / Q000473:pathology / Q000601:surgery*; D023822:Tissue Engineering; D054457:Tissue Scaffolds
chemical_list: D006025:Glycosaminoglycans; D003094:Collagen