title: Targeted delivery of progenitor cells for cartilage repair.
abstract: An approach for promoting the adherence of chondrogenic progenitor cells to specific matrix molecules has been tested in a cartilage defect model. Culture-expanded pre-chondrocytes fluorescently labeled with a vital dye were coated by a two-step method wherein lipidated protein G was first allowed to intercalate into cell membranes, and a second incubation in a solution of antibodies to cartilage matrix antigens allowed the binding of the antibodies to the protein G, on the external surface of the cell. The coating technique (termed "cell painting") does not effect cell viability or inhibit growth and chondrogenic potential. Painted cells were then added to rabbit cartilage explants that had a partial-thickness defect, washed, and prepared for histological examination and for confocal microscopy. The histological observations and the confocal observations and fluorescent intensity quantification consistently demonstrated that progenitor cells painted with multiple antibodies were capable of preferential binding to the exposed cartilage matrix within the defect. These results demonstrate that painting cell membranes with antibodies to matrix molecules is an effective method for promoting the adherence of stem or progenitor cells to a cartilage injury site.
authors.affiliation: Skeletal Research Center, Department of Biology, Case Western Reserve University and University Hospitals of Cleveland, 2080 Adelbert Road, Cleveland, OH 44106-7080, USA. jed4@po.cwru.edu
authors.forename: James E
authors.initials: JE
authors.lastname: Dennis
authors.forename: Nir
authors.initials: N
authors.lastname: Cohen
authors.forename: Victor M
authors.initials: VM
authors.lastname: Goldberg
authors.forename: Arnold I
authors.initials: AI
authors.lastname: Caplan
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000293:injuries / Q000473:pathology*; D002448:Cell Adhesion; D002455:Cell Division / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism / Q000637:transplantation*; D020219:Chondrogenesis; D016326:Extracellular Matrix Proteins / Q000276:immunology; D009419:Nerve Tissue Proteins / Q000276:immunology / Q000494:pharmacology; D011817:Rabbits; D033581:Stem Cell Transplantation / Q000379:methods*; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D016326:Extracellular Matrix Proteins; C029152:G-substrate; D009419:Nerve Tissue Proteins