Tensile mechanical properties of human tracheal cartilage / 中国组织工程研究

ABSTRACT

BACKGROUND:Tracheal injury suture and the development of a new tracheal prosthesis all need to understand the tensile mechanical properties of tracheal cartilage.so as to repair and rebuild tracheal function.Previous researches on the biomechanics of artificial trachea are many reported.while the biomechanics of human tracheal cartilage is reported less.OBJECTIVE:To investigate the mechanical properties of tracheal cartilage using one-dimensional tensile test method.METHODS:Two fresh cadaver specimens of normal human trachea.with the informed consents of their families.were involved.The specimens were thaw at room temperature,and then tracheal cartilage specimens were cut using scalpel into 20 samples at the length of 25 mm,width 5 mm,thickness 1.8-2.2 mm.The 20 tracheal cartilage samples were subjected to one-dimensional tensile test with Shimadzu electronic universal testing machine Japan,at the tensile test speed of 5 mm/min.The tensile maximum load,maximum displacement,maximum stress,maximum strain,elastic modulus and stress-strain curve of the specimens were observed.RESULTS AND CONCLUSION:The maximum load of human cadaver tracheal cartilage was(60 946±10.377)N,maximumdisplacementwas(1.973±0.159)mm,maximum stresswas(6.229±1.125)Mpa,maximum strainwas(32.825±2.776)%.Tracheal cartilage stress-strain curves was changed along with the index,the initial low slope of the curye was due to the direction of imposed tension was similar with the arrangement of collagen structure,the steep slope represented the tensile strength of collagen.To describe the tracheal cartilage stress-strain relationship in a one-dimensional tension,15 stress-strain data of the tracheal cartilage experimental data adopted polynomial by the least square fitting method,to obtain stress(δ)-strain(ε)relationship forrnula:σ(ε)=-0.111 3e~5+1.602 1e~4-7.821 6e~3+17.995 1e~2+3.624e.It is indicated that tracheal cartilage has a strong capacity to bear Joad and resist deformation,reflecting their viscoelastic mechanical properties of both flexibility and viscosity,supporting that the mechanical properties of cartilage is positively related to cartilage collagen content.