title: Characterization of photo-cross-linked oligo[poly(ethylene glycol) fumarate] hydrogels for cartilage tissue engineering.
abstract: Photo-cross-linkable oligo[poly(ethylene glycol) fumarate] (OPF) hydrogels have been developed for use in tissue engineering applications. We demonstrated that compressive modulus of these hydrogels increased with increasing polymer concentration, and hydrogels with different mechanical properties were formed by altering the ratio of cross-linker/polymer in precursor solution. Conversely, swelling of hydrogels decreased with increasing polymer concentration and cross-linker/polymer ratio. These hydrogels are degradable and degradation rates vary with the change in cross-linking level. Chondrocyte attachment was quantified as a method for evaluating adhesion of cells to the hydrogels. These data revealed that cross-linking density affects cell behavior on the hydrogel surfaces. Cell attachment was greater on the samples with increased cross-linking density. Chondrocytes on these samples exhibited spread morphology with distinct actin stress fibers, whereas they maintained their rounded morphology on the samples with lower cross-linking density. Moreover, chondrocytes were photoencapsulated within various hydrogel networks. Our results revealed that cells encapsulated within 2-mm thick OPF hydrogel disks remained viable throughout the 3-week culture period, with no difference in viability across the thickness of hydrogels. Photoencapsulated chondrocytes expressed the mRNA of type II collagen and produced cartilaginous matrix within the hydrogel constructs after three weeks. These findings suggest that photo-cross-linkable OPF hydrogels may be useful for cartilage tissue engineering and cell delivery applications.
authors.affiliation: Tissue Engineering and Polymeric Biomaterials Laboratory, Department of Orthopedic Surgery, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, Minnesota 55905, USA.
authors.forename: Mahrokh
authors.initials: M
authors.lastname: Dadsetan
authors.forename: Jan P
authors.initials: JP
authors.lastname: Szatkowski
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Yaszemski
authors.forename: Lichun
authors.initials: L
authors.lastname: Lu
mesh_terms: D000818:Animals; D002356:Cartilage / Q000166:cytology / Q000254:growth & development*; D002448:Cell Adhesion; D002460:Cell Line; D002470:Cell Survival; D019902:Chondrocytes / Q000737:chemistry / Q000166:cytology* / Q000378:metabolism; D024043:Collagen Type II / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D020100:Hydrogels / Q000138:chemical synthesis / Q000737:chemistry*; D051379:Mice; D010777:Photochemistry; D011091:Polyesters / Q000138:chemical synthesis / Q000528:radiation effects*; D011092:Polyethylene Glycols / Q000138:chemical synthesis / Q000528:radiation effects*; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D013499:Surface Properties; D023822:Tissue Engineering; D014466:Ultraviolet Rays
chemical_list: D024043:Collagen Type II; D020100:Hydrogels; D011091:Polyesters; D012333:RNA, Messenger; C469550:oligo(poly(ethylene glycol)fumarate); D011092:Polyethylene Glycols