Materials (Jan 2020)

TEMPO-Nanocellulose/Ca<sup>2+</sup> Hydrogels: Ibuprofen Drug Diffusion and In Vitro Cytocompatibility

  • Andrea Fiorati,
  • Nicola Contessi Negrini,
  • Elena Baschenis,
  • Lina Altomare,
  • Silvia Faré,
  • Alberto Giacometti Schieroni,
  • Daniele Piovani,
  • Raniero Mendichi,
  • Monica Ferro,
  • Franca Castiglione,
  • Andrea Mele,
  • Carlo Punta,
  • Lucio Melone

DOI
https://doi.org/10.3390/ma13010183
Journal volume & issue
Vol. 13, no. 1
p. 183

Abstract

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Stable hydrogels with tunable rheological properties were prepared by adding Ca2+ ions to aqueous dispersions of 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO)-oxidized and ultra-sonicated cellulose nanofibers (TOUS-CNFs). The gelation occurred by interaction among polyvalent cations and the carboxylic units introduced on TOUS-CNFs during the oxidation process. Both dynamic viscosity values and pseudoplastic rheological behaviour increased by increasing the Ca2+ concentration, confirming the cross-linking action of the bivalent cation. The hydrogels were proved to be suitable controlled release systems by measuring the diffusion coefficient of a drug model (ibuprofen, IB) by high-resolution magic angle spinning (HR-MAS) nuclear magnetic resonance (NMR) spectroscopy. IB was used both as free molecule and as a 1:1 pre-formed complex with β-cyclodextrin (IB/β-CD), showing in this latter case a lower diffusion coefficient. Finally, the cytocompatibility of the TOUS-CNFs/Ca2+ hydrogels was demonstrated in vitro by indirect and direct tests conducted on a L929 murine fibroblast cell line, achieving a percentage number of viable cells after 7 days higher than 70%.

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