Collagen matrices: biomaterials for selective cell response

Dong, Zhe (2017) Collagen matrices: biomaterials for selective cell response. Masters thesis, Memorial University of Newfoundland.

[English] PDF - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. Download (3MB)

Abstract

This thesis covers two types of biomaterials: collagen matrices for cell culture and segmental-long-spacing (SLS) collagen. They are both based on type I collagen, yet have distinct configurations. Cells are supported by extracellular matrix (ECM) proteins which can actively influence differentiation, growth, and function of cells. We used type-I collagen, which is the most abundant fibrous protein in the ECM, to establish a model physical context for cell-cell interaction suitable to study the impacts of fat cells (adipocytes) on breast cancer cells. This model system incorporates interactions with the collagen matrix to selectively manipulate adipocyte development or function as defined by triglyceride accumulation as well as leptin and adiponectin secretion. The morphology and elasticity of collagen matrices in the presence and absence of adipocytes, as measured by atomic force microscopy (AFM), indicates that adipocytes altered collagen elasticity in a manner dependent both on adipocyte developmental stage and the collagen preparation. Overall, it is feasible to selectively manipulate the physiology and functionality of adipocytes by timing the addition of specific collagen overlays in combination with specific tissue-culture plates. These findings have implications for analysis of adipocyte development in vitro as well as potential therapeutic implications to specifically alter adipocyte functionality, which is reported to have impacts on regulating the proliferation of breast cancer cells. As to the SLS collagen, we prepared the samples in different pH environments to seek the influence of pH on the formation of SLS collagen. The result reveals that the less acidic environment (pH=4) favours the formation of long fibers, which is more similar to the native-type configuration of type I collagen aggregation. On the contrary, in the more acidic environment (pH=2), the individual block-like SLS collagen is the major product. Yet, the specific mechanism of the synthesis of SLS collagen still requires more investigation. This work provides the basis for further study to synthesize SLS collagen with tunable length, thickness, and/or surface banding distance, with various applications such as matrices for the cell culture.

Actions (login required)

View Item