Analysis of bending behavior of native and engineered auricular and costal cartilage

Abstract

A large-deflection elasticity model was used to describe the mechanical behavior of cartilaginous tissues during three-point bending tests. Force-deflection curves were measured for 20-mm long x 4-mm wide x approximately 1-mm thick strips of porcine auricular and costal cartilage. Using a least-squares method with elastic modulus in bending as the only adjustable parameter, data were fit to a model based on the von Karman theory for large deflection of plates. This model described the data well, with an average RMS error of 14.8% and an average R(2) value of 0.98. Using this method, the bending modulus of auricular cartilage (4.6 MPa) was found to be statistically lower (p < 0.05) than that of costal cartilage (7.1 MPa). Material features of the cartilage samples influenced the mechanical behavior, including the orientation of the perichondrium in auricular cartilage. These methods also were used to determine the elastic moduli of engineered cartilage samples produced by seeding chondrocytes into fibrin glue. The modulus of tissue-engineered constructs increased statistically with time (p < 0.05), but still were statistically lower than the moduli of the native tissue samples (p > 0.05), reaching only about a third of the values of native samples.

Increased Adipogenesis of Human Adipose-Derived Stem Cells on Polycaprolactone Fiber Matrices

“…This might also play a role in the increased lipid accumulation we find in the PCL-fiber systems, as the fibers are significantly softer, 7.1 MPa±1.3 [61], than tissue culture plastic which has a stiffness of about 2–4 GPa [62]. The fiber-plates have a stiffness resembling that of human cartilage [63], whereas human adipose tissue has a stiffness of 17 Pa [62].…”

Reconstruction of human elastic cartilage by a CD44 + CD90 + stem cell in the ear perichondrium

“…Further evaluations of the extracellular matrix components or mechanical evaluations of the regenerated cartilage will be necessary to show the clinical relevance of perichondrocytes (35,36). However, the use of autologous auricular perichondrocytes represents several important advantages compared with the harvesting of chondrocytes so far.…”

Modeling costal cartilage using local material properties with consideration for gross heterogeneities

“…Many investigations have studied the local material properties of costal cartilage (Feng et al, 2001;Guo et al, 2007;Roy et al, 2004;Abrahams and Duggan, 1964;Mattice et al, 2006;Lau et al, 2008). Up till now, there have been no validating data to indicate how these local material properties affect the structural function of costal cartilage.…”