Comparison of Decellularized and Gamma-Irradiated Septal and Costal Cartilage Allografts in a Rabbit Model

Background: Traditional gamma-irradiated allograft costal cartilage used for cartilage-depleted rhinoplasty patients contains cellular remnants that are potentially responsible for immunological stimulation and graft resorption. Objective: To determine whether decelullarized and/or chemically crosslinked rabbit costal and nasal septal cartilage allografts reduce the risk of allograft resorption. Materials and Methods: In vitro and in vivo analyses of septal and costal cartilage grafts in New Zealand white rabbits were carried out. Irradiated, decellularized, and/or carbodiimide crosslinked cartilage grafts were compared with nontreated autografts and allografts controls. Gross analysis, biomechanical testing, DNA quantification, and histological analyses were performed. Results: All treated grafts had a similar "feel" to native cartilage except for crosslinked grafts, which were significantly stiffer with decreased maximum load and tensile strain. Decellularization effectively reduced DNA content. Biomechanics of explants were unchanged except in untreated allografts, which exhibited increased stiffness, decreased strain, and significant scarring/fibrosis. There was increased glycosaminoglycans retention and less resorption in crosslinked septal cartilage grafts. Conclusion: This study demonstrates the potential benefits of decellularization and crosslinking allograft cartilage and further refinements in crosslinking may improve resorption characteristics while maintaining suitable physical characteristics.