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Figure 1. Morphological and cellular content of decellularized bovine cartilage. (A) Photograph of cartilage samples (Ø 8 mm) before and after decellularization. (B) DNA content and histological H&E stain after decellularization show removal of nuclear materials and reduction in cell remnants. Data shown as mean ± SD for 3 donors, 6 samples per donor. Histological images are representative for all donors. b AC = bovine articular ; b EC = bovine ear cartilage ; UD = Undetectable. (C) Scanning electron microscopy (SEM) shows a highly organized collagen network that remains intact after decellularization ( n =1). seen between the elastin content of decellularized b EC scaffolds compared to untreated b EC ( p =0.535). Histological analysis revealed that after decellularization, elastin was mainly retained directly around lacunae when stained for RF. (Figure 2A) The biomechanical properties of decellularized cartilage scaffolds were assessed using stress-relaxation-indentation. A statistically significant reduction of all compressive parameters was seen in decellularized b EC scaffolds compared to the untreated b EC samples ( p <0.001); Equilibrium modulus (Eeq) of the decellularized b EC scaffolds was 8.7% of the untreated b EC scaffolds. Similarly, maximum stress (σ max ) and relaxation half time (t 1/2 ) were reduced to 9.2% and 32% of the untreated values, respectively. Specifically, σ max in the decellularized b EC scaffolds was 0.54 ± 0.36 MPa and 5.83 ± 2.18 MPa in untreated bEC. t 1/2 in the decellularized b EC samples was 0.74 ± 0.45 s. compared to untreated 2.31 ± 1.5 s. (Figure 2B) Similar changes in matrix integrity and viscoelasticity were seen in the control group consisting of decellularized b AC scaffolds. (Supplementary figure 2) Linear regression analysis was used to correlate ECM components and biomechanical properties. R 2 -values showed that the sGAG, collagen and elastin content of the scaffolds were responsible for more than 50% of the biomechanical properties of decellularized cartilage 138 CHAPTER 7