Design and characterization of hybrid hydrogels composed of imogolite fibrous nanotubular clay and hyaluronic acid

Hybrid hydrogels composed of imogolite fibrous nanotube (IG) and hyaluronic acid (HA) were prepared. Hexamethylenediamine (HMDA) was used as a non-toxic chemical cross-linker. The homogeneous dispersion of IG in the HA solution was accomplished by careful pH control, and subsequent chemical cross-linking provided mechanically stable self-standing hybrid hydrogels. The IG/HA hybrid hydrogels were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), swelling test, compression test, oscillatory rheological analysis, and enzymatic degradation test. The IG/HA hybrid hydrogels show better mechanical properties and lower degradation rate than native HA-based hydrogels without IG hybridization because the cross-linking density increases by incorporation of additional IG network into chemically cross-linked HA network. (C) 2016 Elsevier Ltd. All rights reserved.