Three-dimensional modeling of engineered extracellular matrix derived from collagen
Abstract
Recent evidence supports the notion that biological functions of extracellular matrix (ECM) are highly correlated to not only its composition but also its structure. Defining the fundamental relationships between ECM composition and structure will foster the development of next generation of devices and biomaterials for restoration of tissues and organs (tissue engineering). However, a global problem is accurate quantification of ECM microstructure in 3-D. The lack of such information precludes the derivation of fundamental composition to microstructure and microstructure to mechanical properties. In this study, an EM (Expectation and Maximization) algorithm is first introduced to estimate parameters of mixed density distributions to segment the fibrils from the confocal images. To compute the local orientation and diameter of fibrils as well as the local space size between fibers in the 2-D images, gradient operation methods, line scan methods, and EDM (Euclidean distance map) techniques are implemented. We have demonstrated a new algorithm designed to extract quantitative structural information about individual collagen fibrils (orientation, length, and diameter) from 3-D backscattered-light confocal images of collagen gels. A novel algorithm is validated by computer simulation and statistical analysis. The integration of the algorithm with confocal microscopy imaging techniques allows the quantification of collagen fibril organization in 3-D collagen gels.3D surface-rendered 3D images of the investigated samples are created based on the computed quantitative data. Because collagen polymerization experiments in vitro indicate that pH, ionic strength, and temperature exert profound effects on fibril formation and organization, we have designed a statistical model to investigate the interactive effects of polymerization conditions (pH and concentration) on the structural properties (density and fiber length) of the collagen matrix.
Degree
Ph.D.
Advisors
Robinson, Purdue University.
Subject Area
Biomedical research|Materials science|Biophysics
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