Biomaterials are any matter or material which interacts with biological system which were present on natural or synthetic nonviable materials.... Show moreBiomaterials are any matter or material which interacts with biological system which were present on natural or synthetic nonviable materials. An ideal biomaterial must physically and chemically compatible for biological applications to avoid toxicity and immune reaction. Collagen is a widely abundant, robust biopolymer that is found in the extracellular matrix (ECM) of many tissues. In terms of its structure and organization, collagen is a bio-nano material. The use of collagen in stem cell differentiation is particularly enticing since it is now evident that the extracellular matrix (ECM) proteins can regulate the cell’s fate and growth by their molecular and physical properties. In this thesis research, we have characterized the physical and structural properties of collagen and its composite materials. We found collagen interacts with NaCl and other nano-materials, such as carbon nanotube (CNT) and TiO2 nanotube, resulting in the modification of collagen structure and increase of its stiffness. In particular, CNT has changed collagen structure at both the molecular level and the higher organizational level. The effects of the matrices on cell growth and development were studied. It was found that collagen/CNT matrix specify and accelerate the stem cell differentiation toward neural cells. Since neurons form the foundation of biological circuit, manipulation of neurons in growth has the potential to form desired biological circuit. We also examined collagen in vaginal wall connective tissues, and found that alteration of collagen properties in clinical tissues is correlated to the onset of pelvic organ prolapse. PH.D in Chemistry, May 2013 Show less