| The annulus fibrosus (AF) is beginning to receive attention as a suitable target for tissue engineering (TE) therapies. But due to the AF's complex microstructural and the anisotropic mechanical nature, TE has proven particularly difficult.;In the first specific aim of this work, a set of poly å-caprolactone (PCL) was electrospun at varying degrees of alignment. The individual scaffolds were then characterized in a number of ways (including electron microscopy and multi-directional tensile testing) for the morphological and mechanical properties. This data was then compiled along with the corresponding biocompatibility data collected after culturing these scaffolds with AF cells. And using this data, the best degree of alignment was chosen for AF TE.;In the second specific aim of this work the scaffold preparation parameters that were specified in specific aim one were used to fabricate a scaffold that is optimized for AF TE. This scaffold was then extensively characterized using various imaging, mechanical, and chemical techniques.;In the third specific aim of this work, a novel finite element model using the mechanical homogenization techniques of the human annulus fibrosus (AF) was developed to accurately predict relevant moduli of the AF lamella for tissue engineering application. A general formulation for AF homogenization was laid out with appropriate boundary conditions and using the design characteristics of the fibers that corresponds to the characteristics specified in the first and second specific aims. The geometry of the fiber and matrix were laid out in such a way as to properly mimic the native annulus fibrosus tissue's various, location-dependent geometrical and histological states. The mechanical properties of the annulus fibrosus calculated with this model were then compared with the results obtained from the literature for native tissue. Circumferential, axial, radial, and shear moduli were all in agreement with the values found in literature. |
