title: Meniscal allograft sterilisation: effect on biomechanical and histological properties.
abstract: Sterilisation of allografts are a crucial step in ensuring safety and viability. Current sterilisation standards such as 25 kGy gamma irradiation (γ) can have adverse effects on the ultrastructure and biomechanical properties of allograft tissue. Supercritical CO2 (SCCO2) technology, represents an improved sterilisation process that potentially preserves tissue properties. This study aimed to test the effect of SCCO2 sterilisation on the biomechanical and histological properties of the meniscus and compare this to the current standard of γ. Thirty-two 18-month old ovine menisci were randomly assigned into three groups for sterilisation (SCCO2, γ and control). After treatment, biomechanical indentation testing (stiffness and stress relaxation) or histological analysis [percentage of void, cells and extracellular matrix (ECM) per slide] was undertaken. Both SCCO2 and gamma groups displayed an increase in stiffness and stress relaxation as compared to control, however, this difference was lesser in samples treated with SCCO2. No significant histological quantitative differences were detected between SCCO2 and control specimens. Gamma-treated samples demonstrated a significant increase in void and decrease in ECM. Interestingly, both treatment groups demonstrated a decreasing mean void and increasing ECM percentage when analysed from outer to inner zones. No significant differences were detected in all-endpoints when analysed by section. SCCO2 sterilisation represents a potential feasible alternative to existing sterilization techniques such as γ.
authors.affiliation: Surgical and Orthopaedic Research Laboratories Prince of Wales Clinical School, Prince of Wales Hospital, University of New South Wales, Level 1 Clinical Sciences Building, Avoca St Randwick, Sydney, NSW, 2031, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Bui
authors.forename: Vedran
authors.initials: V
authors.lastname: Lovric
authors.forename: Rema
authors.initials: R
authors.lastname: Oliver
authors.forename: Nicky
authors.initials: N
authors.lastname: Bertollo
authors.forename: David
authors.initials: D
authors.lastname: Broe
authors.forename: William R
authors.initials: WR
authors.lastname: Walsh
mesh_terms: D064591:Allografts / Q000166:cytology* / Q000502:physiology* / Q000528:radiation effects; D000818:Animals; D002245:Carbon Dioxide / Q000494:pharmacology; D048429:Cell Size / Q000187:drug effects / Q000528:radiation effects; D019245:Compressive Strength / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D055119:Elastic Modulus / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D005720:Gamma Rays; D006244:Hardness / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D066298:In Vitro Techniques; D008592:Menisci, Tibial / Q000166:cytology* / Q000502:physiology* / Q000528:radiation effects; D009926:Organ Preservation / Q000379:methods; D012756:Sheep; D013242:Sterilization / Q000379:methods*; D013314:Stress, Mechanical; D013718:Tensile Strength / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D014783:Viscosity
chemical_list: D002245:Carbon Dioxide