title: Effect of swelling ratio of injectable hydrogel composites on chondrogenic differentiation of encapsulated rabbit marrow mesenchymal stem cells in vitro.
abstract: An injectable, biodegradable hydrogel composite of oligo(poly(ethylene glycol) fumarate) (OPF) and gelatin microparticles (MPs) has been investigated as a cell and growth factor carrier for cartilage tissue engineering applications. In this study, hydrogel composites with different swelling ratios were prepared by cross-linking OPF macromers with poly(ethylene glycol) (PEG) repeating units of varying molecular weights from 1000 approximately 35000. Rabbit marrow mesenchymal stem cells (MSCs) and MPs loaded with transforming growth factor-beta1 (TGF-beta1) were encapsulated in the hydrogel composites to examine the effect of the swelling ratio of the hydrogel composites on the chondrogenic differentiation of encapsulated rabbit marrow MSCs both in the presence and in the absence of TGF-beta1. The swelling ratio of the hydrogel composites increased as the PEG molecular weight in the OPF macromers increased. Chondrocyte-specific genes were expressed at higher levels in groups containing TGF-beta1-loaded MPs and varied with the swelling ratio of the hydrogel composites. OPF hydrogel composites with PEG repeating units of molecular weight 35000 and 10000 with TGF-beta1-loaded MPs exhibited a 159 +/- 95- and a 89 +/- 31-fold increase in type II collagen gene expression at day 28, respectively, while OPF hydrogel composites with PEG repeating units of molecular weight 3000 and 1000 with TGF-beta1-loaded MPs showed a 27 +/- 10- and a 17 +/- 7-fold increase in type II collagen gene expression, respectively, as compared to the composites with blank MPs at day 0. The results indicate that chondrogenic differentiation of encapsulated rabbit marrow MSCs within OPF hydrogel composites could be affected by their swelling ratio, thus suggesting the potential of OPF composite hydrogels as part of a novel strategy for controlling the differentiation of stem cells.
authors.affiliation: Department of Bioengineering, Rice University, MS-142, Houston, Texas 77251-1892, USA.
authors.forename: Hansoo
authors.initials: H
authors.lastname: Park
authors.forename: Xuan
authors.initials: X
authors.lastname: Guo
authors.forename: Johnna S
authors.initials: JS
authors.lastname: Temenoff
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Tabata
authors.forename: Arnold I
authors.initials: AI
authors.lastname: Caplan
authors.forename: F Kurtis
authors.initials: FK
authors.lastname: Kasper
authors.forename: Antonios G
authors.initials: AG
authors.lastname: Mikos
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D002454:Cell Differentiation; D019902:Chondrocytes / Q000166:cytology / Q000502:physiology*; D005780:Gelatin / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry* / Q000378:metabolism; D046911:Macromolecular Substances / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000502:physiology*; D008970:Molecular Weight; D010316:Particle Size; D011091:Polyesters / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D011092:Polyethylene Glycols / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D011817:Rabbits; D013499:Surface Properties; D023822:Tissue Engineering; D053773:Transforming Growth Factor beta1 / Q000378:metabolism
chemical_list: D001672:Biocompatible Materials; D046911:Macromolecular Substances; D011091:Polyesters; D053773:Transforming Growth Factor beta1; C469550:oligo(poly(ethylene glycol)fumarate); D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D011092:Polyethylene Glycols; D005780:Gelatin