Tissue Engineering of Hybrid Tissues

Lead Research Organisation: University of Oxford
Department Name: Materials

Abstract

The main objective of this project is to produce a tissue engineered entheses - that is a tendon bone joint. The project will manufacture scaffolds from extra cellular matrix materials and determine their function in guiding stem cells to produce the desired matrix. The end goal is to manufacture a single but compositionally graded scaffold to mimic more closely the structure of an etheses - with one end having similar properties to that of bone and the other closer to that of a tendon. We will examine how the composition of the scaffold, its mechanical properties and its microarchitecture all influence cell response - and more specifically the generation of new tissue. This concept is entirely novel, from the choice of materials to the design of the graded scaffolds.

The extracellular materials of choice will be collagen type 1, elastin, chondroitin sulphate and hydroxyapatite. Initially, single phase scaffolds will be manufactured, characterised and tested. Followed later on by multiphase scaffolds, either crosslinked together or using interlaced microstructures. Techniques for both approaches have been developed and refined in this laboratory. The scaffolds will be characterised by staining methods and conventionally used by biologists and using microanalytical and electron microscopical techniques conventionally used by materials scientists.

We have developed a long standing collaboration with colleagues at the Royal Notional Orthopaedic Hospital at Stanmore where much of the cell work will be performed. The student will learn cell handling techniques there together with immunohistochemistry methods. The student will use stem cells (either human or ovine) to seed their scaffolds. Back in Oxford the mechanical properties of the scaffolds will tested. It will be interesting to see how the stiffness of the scaffold changes for different types of scaffold seed for different lengths of time - up to 28 days. In addition, the change in the shape of the elastic response is seen to be crucial in producing a potentially viable medical device. Any changes in viscous modulus and storage modulus that is developed in any new tissue created by the cells will be examined and investigated. This behaviour has not been explored before and will yield valuable information in how newly formed tissue interacts with the original scaffold.

Overall, the student will learn skills covering a range of materials disciplines, from manufacturing to mechanical properties, microcharacterisation together with cell handling methods.

This project falls within the Healthcare Technologies research area.

Publications

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