title: Co-culture of adipose derived stem cells and chondrocytes with surface modifying proteins induces enhanced cartilage tissue formation.
abstract: OBJECTIVE
  Current treatments for focal cartilage defects include osteochondral allograft transplants-a common treatment for large defects and revisions of previously autografted joints. Allografts with weak osseous regions are usable, since bone remodeling replaces inferior quality bone. However, poor quality chondral surfaces on grafts preclude their use, leading to grafting material shortages. Endogenous adult stem cells can make hyaline-like cartilage tissue on scaffolds. To increase the number of usable allografts, tissue culture methods using adipose derived stem cells (ASCs) were developed to grow cartilage on grafts.
  
  
  METHODS
  Co-cultures utilized living chondrocytes in host cartilage, modeling in vivo conditions, and ASCs seeded on the allografts. Sterilized allografts were treated with Poly-L-Lysine and ProNectin. Tissue growth was analyzed and quantified with histological techniques.
  
  
  CONCLUSIONS
  Monoculture experiments produced tenuous cartilage formation when proteins were utilized and allograft surfaces were perforated. Extensive tissue formation was observed with co-culture and the presence of type II collagen was confirmed with immunohistochemistry. Results demonstrate that co-culture techniques offer a better means of growing tissue on allograft cartilage surfaces. Additionally, the use of proteins to facilitate surface attachment produced more tissue formation demonstrating that cell attachment is crucial when growing cartilage on allografts. Development of new culture techniques to evaluate treatment strategies will accelerate the rate at which cartilage procedures using endogenous cells are possible. This will increase the number of usable grafts and allow critical selection of grafts to fit specific surfaces increasing surgical success by returning the joint to its native structure.
authors.affiliation: Department of Orthopaedic Surgery and Arizona Arthritis Center, College of Medicine, University of Arizona, Tucson, Arizona 85724, USA.
authors.forename: Heather A
authors.initials: HA
authors.lastname: Waters
authors.forename: Chris P
authors.initials: CP
authors.lastname: Geffre
authors.forename: David A
authors.initials: DA
authors.lastname: Gonzales
authors.forename: William A
authors.initials: WA
authors.lastname: Grana
authors.forename: John A
authors.initials: JA
authors.lastname: Szivek
mesh_terms: D017667:Adipocytes / Q000166:cytology; D053687:Adult Stem Cells / Q000166:cytology*; D064591:Allografts; D000818:Animals; D055418:Bone Morphogenetic Protein 6 / Q000494:pharmacology; D002130:Calcium Phosphates / Q000494:pharmacology; D002358:Cartilage, Articular / Q000166:cytology; D002417:Cattle; D019902:Chondrocytes / Q000166:cytology*; D020219:Chondrogenesis; D018920:Coculture Techniques; D004285:Dogs; D004815:Epidermal Growth Factor / Q000494:pharmacology; D005346:Fibroblast Growth Factors / Q000494:pharmacology; D005353:Fibronectins / Q000494:pharmacology; D007596:Joints; D011107:Polylysine / Q000494:pharmacology; D011994:Recombinant Proteins / Q000494:pharmacology; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology; D053782:Transforming Growth Factor beta3 / Q000494:pharmacology
chemical_list: D055418:Bone Morphogenetic Protein 6; D002130:Calcium Phosphates; D005353:Fibronectins; D011994:Recombinant Proteins; D053773:Transforming Growth Factor beta1; D053782:Transforming Growth Factor beta3; C070367:ProNectin F; D011107:Polylysine; D005346:Fibroblast Growth Factors; D004815:Epidermal Growth Factor; C020243:calcium phosphate