A self-healing and multi-responsive hydrogel based on biodegradable ferrocene-modified chitosan

Abstract

Here, we present a novel and facile method for constructing a self-healing hydrogel capable of responding to multiple external stimuli via the self-assembly of biodegradable ferrocene-modified chitosan (FcCS) in an acid aqueous solution at a low concentration of 10 mg mL⁻¹. The hydrogel can re-adhere between cut surfaces and self-heal to its original shape and property after being cut, demonstrating an excellent self-healing property, which is also quantitatively proved by rheological measurements. The hydrogel also presents stimuli-responses towards pH, redox, and different ions such as Cd²⁺, Cr³⁺, Pb²⁺, and Cu²⁺. In addition, the encapsulation and controlled release of doxorubicin hydrochloride (DOX·HCl) in buffer solutions with different pH values were successfully carried out, which suggests that the accumulative release of DOX·HCl increases as the pH value decreases. All these results indicate that this hydrogel is a promising functional and biomedical material.