title: Enhanced cartilage tissue engineering by sequential exposure of chondrocytes to FGF-2 during 2D expansion and BMP-2 during 3D cultivation.
abstract: Bovine calf articular chondrocytes, either primary or expanded in monolayers (2D) with or without 5 ng/ml fibroblast growth factor-2 (FGF-2), were cultured on three-dimensional (3D) biodegradable polyglycolic acid (PGA) scaffolds with or without 10 ng/ml bone morphogenetic protein-2 (BMP-2). Chondrocytes expanded without FGF-2 exhibited high intensity immunostaining for smooth muscle alpha-actin (SMA) and collagen type I and induced shrinkage of the PGA scaffold, thus resembling contractile fibroblasts. Chondrocytes expanded in the presence of FGF-2 and cultured 6 weeks on PGA scaffolds yielded engineered cartilage with 3.7-fold higher cell number, 4.2-fold higher wet weight, and 2.8-fold higher wet weight glycosaminoglycan (GAG) fraction than chondrocytes expanded without FGF-2. Chondrocytes expanded with FGF-2 and cultured on PGA scaffolds in the presence of BMP-2 for 6 weeks yielded engineered cartilage with similar cellularity and size, 1.5-fold higher wet weight GAG fraction, and more homogenous GAG distribution than the corresponding engineered cartilage cultured without BMP-2. The presence of BMP-2 during 3D culture had no apparent effect on primary chondrocytes or those expanded without FGF-2. In summary, the presence of FGF-2 during 2D expansion reduced chondrocyte expression of fibroblastic molecules and induced responsiveness to BMP-2 during 3D cultivation on PGA scaffolds.
authors.affiliation: Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: I
authors.initials: I
authors.lastname: Martin
authors.forename: R
authors.initials: R
authors.lastname: Suetterlin
authors.forename: W
authors.initials: W
authors.lastname: Baschong
authors.forename: M
authors.initials: M
authors.lastname: Heberer
authors.forename: G
authors.initials: G
authors.lastname: Vunjak-Novakovic
authors.forename: L E
authors.initials: LE
authors.lastname: Freed
mesh_terms: D000199:Actins / Q000032:analysis; D000818:Animals; D021522:Bioartificial Organs; D001709:Biotechnology / Q000379:methods*; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology*; D002356:Cartilage / Q000737:chemistry / Q000166:cytology / Q000187:drug effects / Q000254:growth & development*; D002417:Cattle; D018929:Cell Culture Techniques / Q000379:methods*; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D019902:Chondrocytes / Q000737:chemistry / Q000166:cytology / Q000187:drug effects*; D003094:Collagen / Q000032:analysis; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D006025:Glycosaminoglycans / Q000032:analysis; D008853:Microscopy; D011108:Polymers / Q000737:chemistry / Q000378:metabolism; D016212:Transforming Growth Factor beta
chemical_list: D000199:Actins; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D006025:Glycosaminoglycans; D011108:Polymers; D016212:Transforming Growth Factor beta; D016222:Fibroblast Growth Factor 2; D003094:Collagen