title: Tissue engineering strategy using mesenchymal stem cell-based chitosan scafolds in growth plate surgery: a preliminary study in rabbits.
abstract: BACKGROUND
  Growth plate injury in children could produce limb length discrepancy and angular deformity. Removal of damaged physis or bony bar and insertion of spacers produced variable results and for large defects in young children, the treatment is challenging. In this study, we used tissue-engineered mesenchymal stem cells (MSC-based chitosan scaffold) for restoration of the damaged physis. The usage of chitosan as a spacer was also investigated.
  
  
  METHODS
  An experimental model of growth arrest was created by removing lateral 50% of distal femoral physis of fourteen 4-week-olds albino rabbits. The left side growth plate defects were filled with MSC-based chitosan scaffold in 10 and scaffold alone in 4 rabbits. For all the rabbits, right-side defects were left alone as the control limb. After 3 months, femoral bones were harvested and gross inspection and radiology for measurement of angulations were done; histological study for evaluation of regeneration of physis was also done.
  
  
  RESULTS
  The hemiphyseal resection procedures were successful and all of the operated limbs showed angular deformities. There was a trend toward less angular deformity in cases in which more concentration of MSCs with chitosan scaffold was used. In cases of transfer of MSCs with concentration of less than 1.5 millions, mixed results were observed and angular deformities were not reduced. Transfer of chitosan alone yielded poor results.
  
  
  CONCLUSIONS
  In this study, we have developed an in vitro construction of a transplantable tissue-engineered disk, using natural chitosan scaffold and MSCs. We investigated the efficacy of these disks for repairing the defect of growth plate cartilage at distal femoral physis. Our results showed that the beneficial effect of these cells on scaffold appeared in more concentration of cells.
  
  
  METHODS
  Level III. Low power comparative study.
authors.affiliation: Department of orthopedic surgery, Namazee hospital, Shiraz university of medical sciences, Shiraz, Iran.
authors.forename: M R
authors.initials: MR
authors.lastname: Azarpira
authors.affiliation: Department of orthopedic surgery, Namazee hospital, Shiraz university of medical sciences, Shiraz, Iran.
authors.forename: G H
authors.initials: GH
authors.lastname: Shahcheraghi
authors.affiliation: Transplant research center, Shiraz university of medical sciences, Shiraz, Iran; Shiraz stem cell institute for cell therapy and regenerative medicine, Shiraz university of medical sciences, Shiraz, Iran. Electronic address: ayatollmb@yahoo.com.
authors.forename: M
authors.initials: M
authors.lastname: Ayatollahi
authors.affiliation: Transplant research center, Shiraz university of medical sciences, Shiraz, Iran.
authors.forename: B
authors.initials: B
authors.lastname: Geramizadeh
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D048271:Chitosan; D005269:Femur / Q000601:surgery; D006132:Growth Plate / Q000601:surgery*; D045164:Mesenchymal Stem Cell Transplantation; D059630:Mesenchymal Stem Cells / Q000166:cytology; D011817:Rabbits; D000072042:Salter-Harris Fractures; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds
chemical_list: D001672:Biocompatible Materials; D048271:Chitosan
keywords: Chitosan; Growth plate; Mesenchymal stem cells; Tissue-engineering