Use of low-field NMR for the characterization of gels and biological tissues

The focus of this paper is on the theoretical interpretation of Low Field Nuclear Magnetic Resonance (LF-NMR) data regarding hydrogels architecture and on the most interesting applications of LF-NMR presented by this research group at the 6th IAPC Symposium held in Zagreb (HR) on September 2017. Particular attention is devoted to the determination of the mesh size distribution of gels polymeric network and the determination of the pore size distribution of microporous systems such as scaffolds, bones, and porous gels. In addition, we report on a very recent application of LF-NMR for monitoring lung functioning in patients suffering from chronic pulmonary diseases like cystic fibrosis. The main findings of this work consist in providing a very simple and accurate approximation of a general theory devoted to evaluating the relation existing among four fundamental polymeric network parameters, i.e. the polymer volume fraction inside the hydrogel, mesh size, hydraulic radius, and the radius of the cylinder ideally embedding each polymeric network chain. Furthermore, we demonstrated the potentiality of LF-NMR in the characterization of different polymeric systems among which the sputum of patients suffering from chronic pulmonary diseases appears the most innovative application for its simplicity, rapidity, effectiveness, and potential impact in the everyday clinic