Genre: Information/Explanation

Dr Hamid Dehghani " Dr Julian Moger " " Full table of contents Biophysics of the Extracellular Matrix The extracellular matrix is a component of all mammalian tissues and consists of a network of fibrous proteins , elastin and collagens , embedded in a viscoelastic gel rich in high molecular weight anionic polymers known as proteoglycans . This structure , which is quantitatively a major component in tissues such as cartilage , intervertebral disc and blood vessels , endows tissues with the requisite mechanical properties and regulates the movement of water , nutrients and other solutes . There is strong evidence that changes in these functions are associated with diseases as apparently diverse as arthritis , atherosclerosis and cancer . There is a delicate symbiosis between the behaviour of the cells , whose functions include the repair and remodelling of the extracellular matrix , and the composition of the matrix itself . This interaction , which is mediated by a wide variety of electrical , mechanical and chemical signals , is only slowly becoming understood but it underlies the normal processes of development and growth and may be impaired in disease . Our research has the long-term aim of unravelling the relationships between the physical properties of the macromolecular constituents of the extracellular matrix and their supramolecular assemblies and the physiological functions of the tissue . This information is , we believe , important in relating the wealth of descriptive data that has accumulated on changes in extracellular matrix biochemistry that occur in disease to the actual disease process . Current projects include : Analysis of the molecular mechanisms of elasticity in elastic proteins . Characterisation of the organisation of Type IV collagen in the basement membrane and the changes that occur in diabetes . Investigation of the structure and permeability to nutrients of the bone-cartilage interface in normal tissues , osteoporosis and arthritis . Ultrastructural analysis of the stress and strain distribution in bone and cartilage under mechanical loads . Investigation of the effects of ionising radiation on the physical properties of extracellular matrix macromolecules . In this work we employ techniques such as Raman microspectrometry to characterise molecular composition and conformation , small and large angle X-ray diffraction , utilising synchrotron sources , to characterise intra - and supra-molecular organisation and X-ray fluorescence for material characterisation , as well as a number of more specialised techniques , some of which are described in the Biomedical Optics