title: Addition of Mesenchymal Stem Cells to Autologous Platelet-Enhanced Fibrin Scaffolds in Chondral Defects: Does It Enhance Repair?
abstract: BACKGROUND
  The chondrogenic potential of culture-expanded bone-marrow-derived mesenchymal stem cells (BMDMSCs) is well described. Numerous studies have also shown enhanced repair when BMDMSCs, scaffolds, and growth factors are placed into chondral defects. Platelets provide a rich milieu of growth factors and, along with fibrin, are readily available for clinical use. The objective of this study was to determine if the addition of BMDMSCs to an autologous platelet-enriched fibrin (APEF) scaffold enhances chondral repair compared with APEF alone.
  
  
  METHODS
  A 15-mm-diameter full-thickness chondral defect was created on the lateral trochlear ridge of both stifle joints of twelve adult horses. In each animal, one defect was randomly assigned to receive APEF+BMDMSCs and the contralateral defect received APEF alone. Repair tissues were evaluated one year later with arthroscopy, histological examination, magnetic resonance imaging (MRI), micro-computed tomography (micro-CT), and biomechanical testing.
  
  
  RESULTS
  The arthroscopic findings, MRI T2 map, histological scores, structural stiffness, and material stiffness were similar (p > 0.05) between the APEF and APEF+BMDMSC-treated repairs at one year. Ectopic bone was observed within the repair tissue in four of twelve APEF+BMDMSC-treated defects. Defects repaired with APEF alone had less trabecular bone edema (as seen on MRI) compared with defects repaired with APEF+BMDMSCs. Micro-CT analysis showed thinner repair tissue in defects repaired with APEF+BMDMSCs than in those treated with APEF alone (p < 0.05).
  
  
  CONCLUSIONS
  APEF alone resulted in thicker repair tissue than was seen with APEF+BMDMSCs. The addition of BMDMSCs to APEF did not enhance cartilage repair and stimulated bone formation in some cartilage defects.
  
  
  CONCLUSIONS
  APEF supported repair of critical-size full-thickness chondral defects in horses, which was not improved by the addition of BMDMSCs. This work supports further investigation to determine whether APEF enhances cartilage repair in humans.
authors.affiliation: Gail Holmes Equine Orthopedic Research Center, Colorado State University, 300 West Drake Road, Fort Collins, CO 80523.
authors.forename: Laurie R
authors.initials: LR
authors.lastname: Goodrich
authors.affiliation: Department of Bioengineering, Mail Code 0412, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0412.
authors.forename: Albert C
authors.initials: AC
authors.lastname: Chen
authors.affiliation: Large Animal Clinical Sciences, 2015 S.W. 16th Avenue, Gainesville, FL 32608.
authors.forename: Natasha M
authors.initials: NM
authors.lastname: Werpy
authors.affiliation: Department of Orthopedic Surgery, Stanford University School of Medicine, 450 Broadway Street, Redwood City, CA 94063.
authors.forename: Ashley A
authors.initials: AA
authors.lastname: Williams
authors.affiliation: Gail Holmes Equine Orthopedic Research Center, Colorado State University, 300 West Drake Road, Fort Collins, CO 80523.
authors.forename: John D
authors.initials: JD
authors.lastname: Kisiday
authors.affiliation: Department of Bioengineering, Mail Code 0412, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0412.
authors.forename: Alvin W
authors.initials: AW
authors.lastname: Su
authors.affiliation: Department of Bioengineering, Mail Code 0412, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0412.
authors.forename: Esther
authors.initials: E
authors.lastname: Cory
authors.affiliation: Gail Holmes Equine Orthopedic Research Center, Colorado State University, 300 West Drake Road, Fort Collins, CO 80523.
authors.forename: Paul S
authors.initials: PS
authors.lastname: Morley
authors.affiliation: Gail Holmes Equine Orthopedic Research Center, Colorado State University, 300 West Drake Road, Fort Collins, CO 80523.
authors.forename: C Wayne
authors.initials: CW
authors.lastname: McIlwraith
authors.affiliation: Department of Bioengineering, Mail Code 0412, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0412.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Sah
authors.affiliation: Department of Orthopedic Surgery, Stanford University School of Medicine, 450 Broadway Street, Redwood City, CA 94063. chucr@stanford.edu.
authors.forename: Constance R
authors.initials: CR
authors.lastname: Chu
mesh_terms: D000818:Animals; D001182:Arthroscopy / Q000379:methods; D001707:Biopsy, Needle; D001792:Blood Platelets; D002357:Cartilage Diseases / Q000473:pathology / Q000601:surgery*; D002358:Cartilage, Articular / Q000473:pathology / Q000601:surgery*; D004195:Disease Models, Animal; D005337:Fibrin / Q000008:administration & dosage / Q000494:pharmacology*; D005500:Follow-Up Studies; D006736:Horses; D006801:Humans; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging / Q000379:methods; D045164:Mesenchymal Stem Cell Transplantation / Q000379:methods*; D011897:Random Allocation; D023822:Tissue Engineering / Q000379:methods; D054457:Tissue Scaffolds; D014182:Transplantation, Autologous; D016896:Treatment Outcome
chemical_list: D005337:Fibrin