Self-healable and flexible supramolecular gelatin/MoS2 hydrogels with molecular recognition properties

Two-dimensional MoS2 is emerging as a unique platform for a wide range of biomedical applications including extracellular matrix mimics, drug delivery systems and antimicrobial agents. However, low processability and nonspecific interactions at biointerfaces are serious challenges that hamper the biomedical applications of this nanomaterial. Herein, we show how specific interactions between MoS2 and a gelatin matrix results in a biomimetic hydrogel with the self-healing and molecular recognition properties. β-Cyclodextrin was conjugated to the surface of freshly exfoliated MoS2 through a one pot nucleophilic substitution reaction and the obtained cyclodextrin-functionalized MoS2 was used to construct an injectable, self-healable and flexible supramolecular hydrogel upon host-guest interactions with adamantane-modified gelatin matrix. Incorporation of almost 1 wt% of CDMoS2 into gelatin matrix with 1cm2 cross-section resulted in a hydrogel that was able to tolerate one hundred grams. Also, storage modulus (G′), loss modulus (G″) of the obtained hydrogel was 10 and 25 times higher than that for the neat gelatin, respectively. Due to its self-healing, molecular recognition and mechanical properties as well as its flexibility, injectability, and processability, MoS2gel is a promising candidate for a wide range of future biomedical applications including extracellular matrix mimics and tissue engineering.