Giulia Fanesi1, Michela Abrami2, Francesca Zecchin2, Irina Giassi2, Elena Dal Ferro1, Anja Boisen1, Gabriele Grassi3, Paolo Bertoncin4, Mario Grassi5, Paolo Marizza1. 1. Department of Micro- and Nanotechnology, Technical University of Denmark (DTU), Ørsteds Plads Bygning 345Ø, 2800 Kgs, Kongens Lyngby, Denmark. 2. Department of Engineering and Architecture, University of Trieste, Building B, via Valerio 6, I-34127, Trieste, Italy. 3. Department of Life Sciences, Cattinara Hospital, University of Trieste, Strada di Fiume 447, I-34100, Trieste, Italy. 4. Department of Life Sciences, University of Trieste, Piazzale Europa 1, I-34127, Trieste, Italy. 5. Department of Engineering and Architecture, University of Trieste, Building B, via Valerio 6, I-34127, Trieste, Italy. mario.grassi@dia.units.it.
Abstract
PURPOSE: This paper is based on the characterization of the rheological and Low Field NMR (LF-NMR) properties of an interpenetrated hydrogel made up by poly(N-vinyl-2-pyrrolidone) and sodium alginate. The final aim is to use the hydrogel as a delivery matrix for liposomes, widely used tools in the drug delivery field. METHODS: Rheology, LF-NMR, TEM, cryo-TEM, confocal laser scanning microscopy and release test were employed to characterize the interpenetrated hydrogel. Different theoretical approaches such as Flory, Chui, Scherer and Schurz theories were used to interpret the experimental results. RESULTS: We found that the crosslinking mechanisms of the two polymers produced an anti-synergistic effect on the final mechanical properties of the interpenetrated hydrogel. Instead of creating a continuous network, alginate formed isolated, cross-linked, clusters embedded in a continuous network of poly(N-vinyl-2-pyrrolidone). Additionally, gel structure significantly influenced liposome delivery. CONCLUSIONS: The rheological and LF-NMR characterization were confirmed and supported by the independent techniques TEM, cryo-TEM and release tests Thus, our findings reiterate the potentiality of both rheology and LF-NMR for the characterisation of soft materials such as interpenetrated polymeric networks.
PURPOSE: This paper is based on the characterization of the rheological and Low Field NMR (LF-NMR) properties of an interpenetrated hydrogel made up by poly(N-vinyl-2-pyrrolidone) and sodium alginate. The final aim is to use the hydrogel as a delivery matrix for liposomes, widely used tools in the drug delivery field. METHODS: Rheology, LF-NMR, TEM, cryo-TEM, confocal laser scanning microscopy and release test were employed to characterize the interpenetrated hydrogel. Different theoretical approaches such as Flory, Chui, Scherer and Schurz theories were used to interpret the experimental results. RESULTS: We found that the crosslinking mechanisms of the two polymers produced an anti-synergistic effect on the final mechanical properties of the interpenetrated hydrogel. Instead of creating a continuous network, alginate formed isolated, cross-linked, clusters embedded in a continuous network of poly(N-vinyl-2-pyrrolidone). Additionally, gel structure significantly influenced liposome delivery. CONCLUSIONS: The rheological and LF-NMR characterization were confirmed and supported by the independent techniques TEM, cryo-TEM and release tests Thus, our findings reiterate the potentiality of both rheology and LF-NMR for the characterisation of soft materials such as interpenetrated polymeric networks.
Authors: A J Kuijpers; P B van Wachem; M J van Luyn; G H Engbers; J Krijgsveld; S A Zaat; J Dankert; J Feijen Journal: J Control Release Date: 2000-07-03 Impact factor: 9.776
Authors: G Grassi; B Scaggiante; B Dapas; R Farra; F Tonon; G Lamberti; A Barba; S Fiorentino; N Fiotti; F Zanconati; M Abrami; M Grassi Journal: Curr Med Chem Date: 2013 Impact factor: 4.530