title: Fabrication of polycaprolactone collagen hydrogel constructs seeded with mesenchymal stem cells for bone regeneration.
abstract: The osteogenic differentiation of bone marrow-derived human mesenchymal stem cells (MSCs) in a collagen I hydrogel was investigated. Collagen hydrogels with 7.5 x 10(5) MSCs ml(-1) were fabricated and cultured for 6 weeks in a defined, osteogenic differentiation medium. Histochemistry revealed morphologically distinct, chondrocyte-like cells, surrounded by a sulfated proteoglycan-rich extracellular matrix in the group treated with bone morphogenetic protein 2 (BMP-2), while cells cultured with dexamethasone, ascorbate-2-phosphate, and beta-glycerophosphate displayed a spindle-shaped morphology and deposited a mineralized matrix. Real-time polymerase chain reaction (RT-PCR) analyses revealed a specific chondrogenic differentiation with the expression of cartilage-specific markers in the BMP-2-treated group and a distinct expression pattern of the osteogenic markers alkaline phosphatase (ALP), type I collagen, osteocalcin (OC), and cbfa-1 in the group treated with an osteogenic standard medium. The collagen gels were used to engineer a cell laden medical grade epsilon-polycaprolactone (PCL)-hydrogel construct for segmental bone repair showing good bonding at the scaffold hydrogel interface and even cell distribution. The results show that MSCs cultured in a collagen I hydrogel are able to undergo a distinct osteogenic differentiation pathway when stimulated with specific differentiation factors and suggest that collagen I hydrogels are a suitable means to facilitate cell seeding of scaffolds for bone tissue engineering applications.
authors.affiliation: Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia. johannes.reichert@qut.edu.au
authors.forename: J C
authors.initials: JC
authors.lastname: Reichert
authors.forename: A
authors.initials: A
authors.lastname: Heymer
authors.forename: A
authors.initials: A
authors.lastname: Berner
authors.forename: J
authors.initials: J
authors.lastname: Eulert
authors.forename: U
authors.initials: U
authors.lastname: Nöth
mesh_terms: D055396:Bone Morphogenetic Protein 2 / Q000378:metabolism; D001861:Bone Regeneration; D002356:Cartilage / Q000378:metabolism; D002358:Cartilage, Articular / Q000378:metabolism; D002454:Cell Differentiation; D019902:Chondrocytes / Q000378:metabolism; D003094:Collagen / Q000737:chemistry*; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry; D020100:Hydrogels / Q000737:chemistry*; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D015675:Osteocalcin / Q000378:metabolism; D010012:Osteogenesis; D011091:Polyesters / Q000737:chemistry*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D055396:Bone Morphogenetic Protein 2; D020100:Hydrogels; D011091:Polyesters; D015675:Osteocalcin; C016240:polycaprolactone; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D003094:Collagen