title: Assessment of biocompatibility and initial evaluation of genipin cross-linked elastin-like polypeptides in the treatment of an osteochondral knee defect in rabbits.
abstract: Polypeptides based on the alternating hydrophobic and cross-linking domain structure of human elastin are capable of undergoing self-assembly to produce polymeric matrices with unique biological and mechanical properties. Here, we test the initial feasibility of using a genipin cross-linked elastin-based material as an acellular plug in the treatment of an osteochondral defect in the rabbit knee. Full-thickness defects in the weight-bearing surface of the medial femoral condyle in 18 New Zealand White rabbits were surgically produced and press fitted with cylindrical pads composed of genipin cross-linked elastin-like polypeptides, with identical wounds in the opposite knee left untreated as controls. The biocompatibility of the material, overall wound healing and regeneration of subchondral tissue was assessed at 2, 4 and 6weeks by histological evaluation, synovial fluid analysis and microcomputerized tomography scanning. Histological analysis revealed the regeneration of subchondral bone at the periphery of the material, with evidence of hyaline-like overgrowth across the apical surface in 11/16 cases. Pads developed tight contacts with host tissue and appeared completely biocompatible, with no evidence of localized immune response or increased inflammation compared to controls. The material was stable to 6weeks, with an aggregate elastic modulus calculated at approximately 470kPa when tested under confined compression. Further studies are required to assess material degradation over time and long-term replacement with repair tissue.
authors.affiliation: Elastin Specialties Inc., 101 College Street, Toronto, Ont., Canada M5S 3E5.
authors.forename: Christopher
authors.initials: C
authors.lastname: Hrabchak
authors.forename: Jessica
authors.initials: J
authors.lastname: Rouleau
authors.forename: Isaac
authors.initials: I
authors.lastname: Moss
authors.forename: Kimberly
authors.initials: K
authors.lastname: Woodhouse
authors.forename: Margarete
authors.initials: M
authors.lastname: Akens
authors.forename: Catherine
authors.initials: C
authors.lastname: Bellingham
authors.forename: Fred
authors.initials: F
authors.lastname: Keeley
authors.forename: Madison
authors.initials: M
authors.lastname: Dennis
authors.forename: Albert
authors.initials: A
authors.lastname: Yee
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000008:administration & dosage* / Q000737:chemistry; D003432:Cross-Linking Reagents / Q000737:chemistry; D004343:Drug Implants / Q000008:administration & dosage* / Q000737:chemistry; D055119:Elastic Modulus; D004549:Elastin / Q000008:administration & dosage* / Q000737:chemistry*; D006244:Hardness; D057889:Iridoid Glycosides; D039823:Iridoids / Q000008:administration & dosage* / Q000737:chemistry*; D008422:Materials Testing; D010007:Osteochondritis / Q000188:drug therapy* / Q000473:pathology; D010455:Peptides / Q000008:administration & dosage / Q000737:chemistry; D011817:Rabbits; D013499:Surface Properties; D016896:Treatment Outcome
chemical_list: D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D004343:Drug Implants; D057889:Iridoid Glycosides; D039823:Iridoids; D010455:Peptides; D004549:Elastin; C007834:genipin