(395c) Oriented Matrices of Collagen for Directed Cellular Growth

The most prevalent protein found in the human body is collagen, which subsides mainly in connective tissues (tendons) and load bearing tissues such as bone and teeth. A collagen molecule itself is a rod-like molecule of about 300 nm in length and 1.5 nm in diameter. The molecular structure consists of three polypeptide strands wound in a left-handed triple helix. The rod-like molecule can self-assemble and transition from an isotropic phase into a highly oriented liquid crystal. The distinct liquid crystalline structures can be observed in many natural tissues such as bone, tendon, and human dermis. This research focuses on the production of a biocompatible substrate that can dictate cellular level control but also have similar mechanical properties of the natural tissues, such as tensile strength and flexibility.

We have been able to manipulate the self-assembly of collagen molecules into various architectures using different flow processing techniques. The hydrodynamic forces orient the collagen molecules parallel to the flow direction prior to fiber formation, resulting in oriented gels of collagen. These oriented structures have demonstrated effective contact guidance of adult human fibroblasts where the cell bodies polarize their cytoskeleton along the direction of the fibers. In addition, the collagen matrices can retain their orientation while the surface is modified for different chemical or structural properties, adding versatility to these oriented structures of collagen. Chemical attachment of molecules, such as growth factors, onto the collagen substrates can attract the growth of cells along the oriented structures. The oriented collagen gels may also undergo crosslinking treatments to enhance their structural properties. A scaffold or substrate that has the ability to encourage attachment and proliferation of cells is an important step for the progression of finding compatible tissue replacements and biomimetic materials.