Self-Healing Hydrogels of Low Molecular Weight Poly(vinyl alcohol) Assembled by Host-Guest Recognition.

Poly(vinyl alcohol) (PVA) is a cytocompatible synthetic polymer and has been commonly used to prepare hydrogels. Bile acids and β-cyclodextrin are both natural compounds and they form stable host-guest inclusion complexes. They are attached covalently onto a low molecular weight PVA separately. Self-healing hydrogels can be easily formed by mixing the aqueous solutions of these PVA based polymers. The mechanical properties of the hydrogels can be tuned by varying the molar fractions of bile acid units on PVA. The dynamic inclusion complexation of the host-guest pair of the hydrogel allows the self-healing rapidly under ambient atmosphere and their mechanical properties could recover their original values in 1 min after incision. These PVA based polymers exhibited the good cytocompatibility and high hemocompatibility as shown by their biological evaluations. The use of natural compounds for host-guest interaction make such gels especially convenient to use as biomaterials, an advantage over conventional hydrogels prepared through freeze-thaw method.