title: Transport Properties of Ibuprofen Encapsulated in Cyclodextrin Nanosponge Hydrogels: A Proton HR-MAS NMR Spectroscopy Study.
abstract: The chemical cross-linking of β-cyclodextrin (β-CD) with ethylenediaminetetraacetic dianhydride (EDTA) led to branched polymers referred to as cyclodextrin nanosponges (CDNSEDTA). Two different preparations are described with 1:4 and 1:8 CD-EDTA molar ratios. The corresponding cross-linked polymers were contacted with 0.27 M aqueous solution of ibuprofen sodium salt (IP) leading to homogeneous, colorless, drug loaded hydrogels. The systems were characterized by high resolution magic angle spinning (HR-MAS) NMR spectroscopy. Pulsed field gradient spin echo (PGSE) NMR spectroscopy was used to determine the mean square displacement (MSD) of IP inside the polymeric gel at different observation times td. The data were further processed in order to study the time dependence of MSD: MSD = f(td). The proposed methodology is useful to characterize the different diffusion regimes that, in principle, the solute may experience inside the hydrogel, namely normal or anomalous diffusion. The full protocols including the polymer preparation and purification, the obtainment of drug-loaded hydrogels, the NMR sample preparation, the measurement of MSD by HR-MAS NMR spectroscopy and the final data processing to achieve the time dependence of MSD are here reported and discussed. The presented experiments represent a paradigmatic case and the data are discussed in terms of innovative approach to the characterization of the transport properties of an encapsulated guest within a polymeric host of potential application for drug delivery.
authors: Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano.
authors: Monica
authors: M
authors: Ferro
authors: Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano.
authors: Franca
authors: F
authors: Castiglione
authors: Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano.
authors: Carlo
authors: C
authors: Punta
authors: Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano; Università degli studi e-Campus.
authors: Lucio
authors: L
authors: Melone
authors: ICRM, CNR - Consiglio Nazionale delle Ricerche.
authors: Walter
authors: W
authors: Panzeri
authors: Elettra Sincrotrone Trieste.
authors: Barbara
authors: B
authors: Rossi
authors: Department of Chemistry, University of Torino.
authors: Francesco
authors: F
authors: Trotta
authors: Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano; andrea.mele@polimi.it.
authors: Andrea
authors: A
authors: Mele
mesh_terms: D003505:Cyclodextrins / Q000737:chemistry*; D020100:Hydrogels; D007052:Ibuprofen / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D011522:Protons
chemical_list: D003505:Cyclodextrins; D020100:Hydrogels; D011522:Protons; D007052:Ibuprofen