Berlin 2018 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
BP: Fachverband Biologische Physik
BP 2: Biomaterials and Biopolymers (joint session BP/CPP)
BP 2.1: Vortrag
Montag, 12. März 2018, 09:30–09:45, H 1058
PFG-NMR studies of ATP diffusion in PEG-DA hydrogels and aqueous solutions of PEG-DA polymers — •Günter Majer1 and Alexander Southan2 — 1MPI für Intelligente Systeme, Heisenbergstr. 3, 70569 Stuttgart, Germany — 2Institut für Grenzflächenverfahrenstechnik und Plasmatechnologie IGVP, Universität Stuttgart, Nobelstraße 12, 70569 Stuttgart, Germany
Adenosine triphosphate (ATP) is the major carrier of chemical energy in cells. The diffusion of ATP in hydrogels, which have a structural resemblance to the natural extracellular matrix, is therefore of great importance for understanding many biological processes. A powerful tool to determine the diffusion coefficients of ATP and other solutes directly, i.e. without the need for a fluorescent label and independent of any diffusion-model assumptions, is pulsed field gradient nuclear magnetic resonance (PFG-NMR). We present precise PFG-NMR measurements of ATP diffusion in PEG-DA hydrogels of various mesh sizes as well as in aqueous solutions of PEG-DA polymers, which are not cross-linked to a three-dimensional network. A major result of this work is that the diffusion coefficients are determined by the polymer volume fraction only, regardless of whether the polymers are cross-linked or not. Obviously, the ATP diffusion takes place only in the aqueous regions of the systems, with the volume fraction of the polymers, including a solvating water layer, being blocked for the ATP molecules. This modified obstruction model is most appropriate to correctly describe ATP diffusion in PEG-DA hydrogels.