TY - JOUR
T1 - Viscoelastic and biomechanical properties of osteochondral tissue constructs generated from graded polycaprolactone and beta-tricalcium phosphate composites
AU - Erisken, Cevat
AU - Kalyon, Dilhan M.
AU - Wang, Hongjun
PY - 2010/9
Y1 - 2010/9
N2 - The complex micro-/nanostructure of native cartilage-to-bone insertion exhibits gradations in extracellular matrix components, leading to variations in the viscoelastic and biomechanical properties along its thickness to allow for smooth transition of loads under physiological movements. Engineering a realistic tissue for osteochondral interface would, therefore, depend on the ability to develop scaffolds with properly graded physical and chemical properties to facilitate the mimicry of the complex elegance of native tissue. In this study, polycaprolactone nanofiber scaffolds with spatially controlled concentrations of β-tricalcium phosphate nanoparticles were fabricated using twin-screw extrusion-electrospinning process and seeded with MC3T3-E1 cells to form osteochondral tissue constructs. The objective of the study was to evaluate the linear viscoelastic and compressive properties of the native bovine osteochondral tissue and the tissue constructs formed in terms of their small-amplitude oscillatory shear, unconfined compression, and stress relaxation behavior. The native tissue, engineered tissue constructs, and unseeded scaffolds exhibited linear viscoelastic behavior for strain amplitudes less than 0.1%. Both native tissue and engineered tissue constructs demonstrated qualitatively similar gel-like behavior as determined using linear viscoelastic material functions. The normal stresses in compression determined at 10% strain for the unseeded scaffold, the tissue constructs cultured for four weeks, and the native tissue were 0.87 ± 0.08 kPa, 3.59 ± 0.34 kPa, and 210.80 ± 8.93 kPa, respectively. Viscoelastic and biomechanical properties of the engineered tissue constructs were observed to increase with culture time reflecting the development of a tissuelike structure. These experimental findings suggest that viscoelastic material functions of the tissue constructs can provide valuable inputs for the stages of in vitro tissue development.
AB - The complex micro-/nanostructure of native cartilage-to-bone insertion exhibits gradations in extracellular matrix components, leading to variations in the viscoelastic and biomechanical properties along its thickness to allow for smooth transition of loads under physiological movements. Engineering a realistic tissue for osteochondral interface would, therefore, depend on the ability to develop scaffolds with properly graded physical and chemical properties to facilitate the mimicry of the complex elegance of native tissue. In this study, polycaprolactone nanofiber scaffolds with spatially controlled concentrations of β-tricalcium phosphate nanoparticles were fabricated using twin-screw extrusion-electrospinning process and seeded with MC3T3-E1 cells to form osteochondral tissue constructs. The objective of the study was to evaluate the linear viscoelastic and compressive properties of the native bovine osteochondral tissue and the tissue constructs formed in terms of their small-amplitude oscillatory shear, unconfined compression, and stress relaxation behavior. The native tissue, engineered tissue constructs, and unseeded scaffolds exhibited linear viscoelastic behavior for strain amplitudes less than 0.1%. Both native tissue and engineered tissue constructs demonstrated qualitatively similar gel-like behavior as determined using linear viscoelastic material functions. The normal stresses in compression determined at 10% strain for the unseeded scaffold, the tissue constructs cultured for four weeks, and the native tissue were 0.87 ± 0.08 kPa, 3.59 ± 0.34 kPa, and 210.80 ± 8.93 kPa, respectively. Viscoelastic and biomechanical properties of the engineered tissue constructs were observed to increase with culture time reflecting the development of a tissuelike structure. These experimental findings suggest that viscoelastic material functions of the tissue constructs can provide valuable inputs for the stages of in vitro tissue development.
KW - Electrospinning
KW - Functionally graded
KW - Interface
KW - Osteochondral
KW - Scaffold
KW - Tissue engineering
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U2 - 10.1115/1.4001884
DO - 10.1115/1.4001884
M3 - Article
C2 - 20815647
AN - SCOPUS:77956822724
SN - 0148-0731
VL - 132
JO - Journal of Biomechanical Engineering
JF - Journal of Biomechanical Engineering
IS - 9
M1 - 91013-1
ER -