The mechanical behavior of soft connective tissue is governed by a dense network of fibrillar proteins in the extracellular matrix. Characterization of this fibrous network requires the accurate extraction of descriptive structural parameters from imaging data, including fiber dispersion and mean fiber orientation. Common methods to quantify fiber parameters include fast Fourier transforms (FFT...

HYPOTHESIS Fibroblasts, not myofibroblasts, are responsible for wound contraction. Only myofibroblasts express a smooth muscle actin for which vanadate blocks its expression. Wound contraction in vanadate-treated rats will proceed normally in the absence of myofibroblasts. DESIGN Laboratory study using rats. METHODS Wound healing in rats receiving vanadate parenterally, an inhibitor of tyro...

Changes in the local mechanical environment and tissue mechanical properties affect the biological activity of cells and play a key role in a variety of diseases, such as cancer, arthritis, nephropathy, and cardiovascular disease. Constitutive relations have long been used to predict the local mechanical environment within biological tissues and to investigate the relationship between biologica...

Purpose The purpose of this study was to leverage polarized light microscopy (PLM) to visualize the collagen fiber architecture of posterior pole and optic nerve head with micrometer-scale resolution and to identify and quantify major organizational components. Methods Eight sheep posterior poles were cryosectioned and imaged using PLM. Collagen fiber orientation was determined by using custo...

Hyaline cartilage and mechanically inferior fibrocartilage consisting of mixed collagen types are frequently found together in repairing articular cartilage. The present study seeks to develop methodology to identify collagen type and other tissue components using Fourier transform infrared (FTIR) spectral evaluation of matrix composition in combination with multivariate analyses. FTIR spectra ...

Point-scanning sum-frequency generation (SFG) microscopy enables the generation of images of collagen I fibers in tissues by tuning into specific vibrational resonances of the polypeptide. It is shown that when collagen-rich tissues are visualized near the 2954 cm(-1) stretching vibration of methylene groups, the SFG image contrast is higher compared to the contrast seen in nonresonant second-h...

Dynamic analysis of an axially stretched arterial wall with collagen fibers distributed in two preferred directions under a suddenly applied constant internal pressure along with the possibility of the formation and rupture of aneurysm are examined within the framework of nonlinear dynamics. A two layer tube model with the fiber-reinforced composite-based incompressible anisotropic hyper-elasti...

Type I collagen abounds in mammalian extracellular matrix (ECM) and is crucial to many biophysical processes. While previous studies have mostly focused on bulk averaged properties, here we provide a comprehensive and quantitative spatial-temporal characterization of the microstructure of type I collagen-based ECM as the gelation temperature varies. The structural characteristics including the ...

The arterial wall is a composite where the preferred orientation of collagen fibers induces anisotropy. Though the hyperelastic theories of fiber-reinforced composites reached a high level of sophistication and showed a reasonable correspondence with the available experimental data they are short of the failure description. Following the tradition of strength of materials the failure criteria a...