Salt-Resistant Composite Colloidal Gels Stabilized by Host-Guest Interaction.

Colloidal gels are three-dimensional networks formed by nanoparticles, which have attracted great attention for applications in tissue engineering and regenerative medicine due to their excellent viscoelastic properties. Usually, they are formed by attractive electrostatic interactions between oppositely charged particles. However, high ionic strength of physiological fluids may disrupt the networks by screening electrostatic interactions resulting in gel instability, thereby limiting practical applicability. Herein, we report the fabrication of novel colloidal gels stabilized by host-guest interactions between gelatin nanoparticles functionalized with either β-cyclodextrin or adamantane as building blocks. These host-guest stabilized colloidal gels exhibit repeatable self-healing capability (∼100%) in NaCl solutions of high ionic strength similar to physiological fluids (150 mM), surfactant solutions and cell culture medium. Furthermore, these gels are cytocompatible and promote proliferation and migration of HUVECs and L929 cells. Consequently, this work provides a promising new strategy for extending biomedical applicability of colloidal gels.