title: Photocrosslinked tyramine-substituted hyaluronate hydrogels with tunable mechanical properties improve immediate tissue-hydrogel interfacial strength in articular cartilage.
abstract: Articular cartilage lacks the ability to self-repair and a permanent solution for cartilage repair remains elusive. Hydrogel implantation is a promising technique for cartilage repair; however for the technique to be successful hydrogels must interface with the surrounding tissue. The objective of this study was to investigate the tunability of mechanical properties in a hydrogel system using a phenol-substituted polymer, tyramine-substituted hyaluronate (TA-HA), and to determine if the hydrogels could form an interface with cartilage. We hypothesized that tyramine moieties on hyaluronate could crosslink to aromatic amino acids in the cartilage extracellular matrix. Ultraviolet (UV) light and a riboflavin photosensitizer were used to create a hydrogel by tyramine self-crosslinking. The gel mechanical properties were tuned by varying riboflavin concentration, TA-HA concentration, and UV exposure time. Hydrogels formed with a minimum of 2.5 min of UV exposure. The compressive modulus varied from 5 to 16 kPa. Fluorescence spectroscopy analysis found differences in dityramine content. Cyanine-3 labelled tyramide reactivity at the surface of cartilage was dependent on the presence of riboflavin and UV exposure time. Hydrogels fabricated within articular cartilage defects had increasing peak interfacial shear stress at the cartilage-hydrogel interface with increasing UV exposure time, reaching a maximum shear stress 3.5× greater than a press-fit control. Our results found that phenol-substituted polymer/riboflavin systems can be used to fabricate hydrogels with tunable mechanical properties and can interface with the surface tissue, such as articular cartilage.
authors.affiliation: a Laboratory for Soft Tissue Research , Hospital for Special Surgery , New York , NY , USA.|b Department of Biomechanics , Hospital for Special Surgery , New York , NY , USA.
authors.forename: Patrick E
authors.initials: PE
authors.lastname: Donnelly
authors.affiliation: a Laboratory for Soft Tissue Research , Hospital for Special Surgery , New York , NY , USA.|b Department of Biomechanics , Hospital for Special Surgery , New York , NY , USA.
authors.forename: Tony
authors.initials: T
authors.lastname: Chen
authors.affiliation: a Laboratory for Soft Tissue Research , Hospital for Special Surgery , New York , NY , USA.
authors.forename: Anthony
authors.initials: A
authors.lastname: Finch
authors.affiliation: b Department of Biomechanics , Hospital for Special Surgery , New York , NY , USA.
authors.forename: Caroline
authors.initials: C
authors.lastname: Brial
authors.affiliation: a Laboratory for Soft Tissue Research , Hospital for Special Surgery , New York , NY , USA.|b Department of Biomechanics , Hospital for Special Surgery , New York , NY , USA.
authors.forename: Suzanne A
authors.initials: SA
authors.lastname: Maher
authors.affiliation: a Laboratory for Soft Tissue Research , Hospital for Special Surgery , New York , NY , USA.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Torzilli
mesh_terms: D000464:Alginates / Q000737:chemistry* / Q000378:metabolism; D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism; D001861:Bone Regeneration; D002358:Cartilage, Articular / Q000378:metabolism*; D002448:Cell Adhesion; D018929:Cell Culture Techniques; D019902:Chondrocytes; D003432:Cross-Linking Reagents / Q000737:chemistry*; D055119:Elastic Modulus / Q000502:physiology; D005109:Extracellular Matrix / Q000737:chemistry; D006801:Humans; D006820:Hyaluronic Acid / Q000737:chemistry* / Q000378:metabolism; D020100:Hydrogels / Q000737:chemistry* / Q000378:metabolism; D008027:Light; D008422:Materials Testing / Q000379:methods; D055595:Mechanical Phenomena; D055668:Photochemical Processes; D012256:Riboflavin / Q000737:chemistry; D013499:Surface Properties; D023822:Tissue Engineering / Q000379:methods; D014439:Tyramine / Q000737:chemistry*
chemical_list: D000464:Alginates; D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D020100:Hydrogels; C118495:hyaluronate alginate; D006820:Hyaluronic Acid; D012256:Riboflavin; D014439:Tyramine
keywords: Photocrosslinking; biomaterials; cartilage; hyaluronic acid; hydrogel; riboflavin