Injectable Silk Fibroin-Puerarin Hydrogels with Tunable Supramolecular Organization as a Potential Platform for...

Injectable supramolecular hydrogels represent an emerging class of biomaterials with significant potential for minimally invasive tissue engineering and drug delivery applications. In this study, the effects of varying puerarin (PUE, 1-5%) contents, a bioactive isoflavonoid capable of gelation, on the physicochemical and in vitro biological properties of silk fibroin (SF) were systematically evaluated. Hydrogel formation was driven by hydrogen-bonding interactions between SF and PUE, as confirmed by FTIR analysis, without altering the crystalline structure of SF, as evidenced by X-ray diffraction. Microstructural analysis by scanning electron microscopy (SEM) revealed that increasing PUE content progressively reduced pore size and generated a denser polymeric network, resulting in a decrease in swelling capacity. Thermal analyses (TGA/DSC) demonstrated the combined thermal stability and degradation behavior of the resulting system. Rheological characterization showed a marked increase in viscosity and a predominance of storage modulus (G') over loss modulus (G″), indicating the formation of a mechanically stable supramolecular network with tunable viscoelastic properties and injectability. In vitro biological assays demonstrated that the hydrogels are cytocompatible with HDF cells. Moreover, in vitro scratch assays demonstrated cell migration and complete wound closure within 72 h. In summary, the results demonstrate that PUE incorporation modulates the supramolecular organization and physicochemical properties of SF hydrogels in a concentration-dependent manner, enabling tunable and cytocompatible injectable systems with potential relevance for soft tissue biomaterial applications.