A T 2 D TDNMR study of skin

• Main Authors: Bent, Julian, Lee, Joanna, Benson, Tim
• Other Authors: Unilever Research Colworth,
• Format: Article
• Language: English
• Published: Universitätsbibliothek Leipzig 2015
• Subjects: Diffusion; Transport; diffusion; transport; ddc:530
• Online Access: http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-186435; http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-186435; http://www.qucosa.de/fileadmin/data/qucosa/documents/18643/diff_fund_14%282010%299.pdf

T2D TDNMR data is used to improve the assignment of the location of water in in-vitro pig skin. Whilst the corresponding 1d experiments report broad distributions of T2 and D respectively, two water components are resolved in the T2D data and are assigned as intraand extra-cellular water by considering the peak intensities in; whole defatted skin, a dermatomed slice of the top 0.4mm (mostly epidermis) and the remaining sub layer (dermis). The relative proportion of fast relaxing/fast diffusing water is largest in the epidermis section (which has a close packed cellular structure) so is assigned as intra-cellular water. Whilst there is more slowly relaxing/slowly diffusing water in the dermis section (which has fewer cells within a collagen network) so this is assigned as extra-cellular water. The observation that intra-cellular water relaxes fastest, suggests that the skin cells contain more exchangeable species, through which the water can relax, than the extra-cellular network. This assignment is supported when resolution is lost on repeated freezing, i.e. the cell walls are broken. Resolution is also lost on increasing the diffusion time from 50 to 100 and 150ms. This is likely partly due to relaxation but also due to diffusion through the cell membranes during the experiment and gives a measure of the cell wall permeability.