title: Physicobiochemical synergism through gene therapy and functional tissue engineering for in vitro chondrogenesis.
abstract: Mechanical and chemical stimulation have been shown to enhance in vitro chondrogenesis. The aim of this study was to analyze and compare combined physicobiochemical effects. Bovine articular chondrocytes were retrovirally transduced to express bone morphogenetic protein-2 (BMP-2) or left as naïve controls. Cells were seeded in three-dimensional polyurethane scaffolds and further cultured under static conditions or exposed to dynamic compression and shear in a joint-specific bioreactor. Four groups: control (A), load (B), BMP-2-infected (C), and BMP-2-infected plus load (D) were analyzed for DNA and glycosaminoglycan (GAG) content; collagen I, II, and X; aggrecan, (cartilage oligomeric protein (COMP), superficial zone protein, matrix metalloproteinase (MMP)-3; MMP-13 mRNA; histology; and immunohistochemistry at 7, 21, and 35 days post-seeding. Synergistic effects (D) were higher than the sum of the individual treatments (B and C) for GAG/DNA, collagen II, and COMP. Histology revealed a functional organization in D including an intense safranin O staining in C and D superior to that in A and B. Immunostaining for collagen II and aggrecan was detected in C and D and was strongest in D. The results show that both stimuli augment in vitro chondrogenesis better than in controls. Biochemical manipulation proved to be predominantly more effective than load, and synergistic effects were demonstrated.
authors.affiliation: Department of Orthopaedic and Trauma Surgery, University Medical Center, Albert-Ludwigs University Freiburg, Freiburg, Germany. giansalzmann@yahoo.com
authors.forename: Gian M
authors.initials: GM
authors.lastname: Salzmann
authors.forename: Benedikt
authors.initials: B
authors.lastname: Nuernberger
authors.forename: Philipp
authors.initials: P
authors.lastname: Schmitz
authors.forename: Martina
authors.initials: M
authors.lastname: Anton
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Stoddart
authors.forename: Sibylle
authors.initials: S
authors.lastname: Grad
authors.forename: Stefan
authors.initials: S
authors.lastname: Milz
authors.forename: Thomas
authors.initials: T
authors.lastname: Tischer
authors.forename: Stephan
authors.initials: S
authors.lastname: Vogt
authors.forename: Bernd
authors.initials: B
authors.lastname: Gansbacher
authors.forename: Andreas B
authors.initials: AB
authors.lastname: Imhoff
authors.forename: Mauro
authors.initials: M
authors.lastname: Alini
mesh_terms: D000818:Animals; D002417:Cattle; D019902:Chondrocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D020219:Chondrogenesis / Q000187:drug effects; D016616:Cryoultramicrotomy; D004247:DNA / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D015316:Genetic Therapy; D006025:Glycosaminoglycans / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000378:metabolism; D007150:Immunohistochemistry; D011140:Polyurethanes / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D023822:Tissue Engineering; D054457:Tissue Scaffolds; D014161:Transduction, Genetic
chemical_list: D006025:Glycosaminoglycans; D011140:Polyurethanes; D012333:RNA, Messenger; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D004247:DNA