The self-diffusion behavior of polyethylene glycol in cartilageas studied by pulsed-field gradient NMR

The self-diffusion behavior of the polyethylene glycol (PFG) polymer in bovine nasal cartilage was studied by pulsed-field gradient (PFG) nuclear magnetic resonance (NMR). PFG NMR allows the determination of the mean square displacement of molecules in a given diffusion time (in the range of a few milliseconds up to seconds), monitors distances in micrometer scales and has the advantage of being non-invasive. Moreover the application of pfg nmr does not require concentration gradients In a previous study, PFG NMR was used to investigate the self-diffusion behavior of the PEG polymer in cartilage at very highconcentrations. In this study, much lower PRG concentrations were used in order to detect the effects of the structural composition of the cartilage tissue more efficiently. It will be shown that at very low (<10 wt.-%) PFG concentrations, the effect of restricted polymer diffusion in cartilage is negligible. The self-diffusion coefficients (SDC) are primarily influenced by the water content and the molecular weight (MW) of the appliec. PFG. The problems encountered with PFG NMR diffusion studies using high field gradients as well as in vivo aspects of this study are discussed.