Characterization of hydrogels made of a novel recombinant spider silk proteins MaNC and evaluation for drug carriers

Abstract

Owing to their good biocompatibility and low immunogenicity, spider silk proteins (spidroins) are promising biopolymers with high potential for various medical applications. Of these material types, spidroin-based hydrogels have attracted significant attention in biomaterials research owing to their non-toxic and excellent mechanical properties. However, reported spidroin hydrogels require extended gelation times. In this study, we engineered a novel recombinant spidroin (MaNC) by fusing the highly soluble N-terminal domain and the self-assembling C-terminal domain derived from major ampullate spidroin. The N-terminal domain confers high solubility on MaNC, while the C-terminal domain provides self-assembly properties, enabling rapid gelation of MaNC. We demonstrated that it spontaneously self-assembles into hydrogels at 37 °C within 10 min, accompanied by the formation of β-sheet structure, without requiring any external additives. It was shown that the self-assembling MaNC hydrogels exhibit no swelling, can be readily loaded with doxorubicin under aqueous conditions, release drug over one month, and that the diffusion rate can be tuned by changing the protein concentration and pH value. Collectively, these data support the notion that our silk hydrogels are fast-gelling, highly adaptable, and cytocompatible materials that self-assemble under mild conditions and are well suited for chemotherapy delivery.