Biofunctional silk sericin hydrogels: A versatile platform with potential for tissue healing and regeneration

Discarded silk sericin protein (SS) presents a high yet underexplored potential as a biomaterial for tissue engineering (TE). Despite its biocompatibility, antioxidant activity, and moisture retention properties, its poor stability in aqueous media has limited broader application. In this work, we developed and characterized SS-based hydrogels using tannic acid (TA) and horseradish peroxidase (HRP) crosslinking systems to address these limitations and expand their use in skin TE. Hydrogels were prepared using SS concentrations of 2.5 % and 5 % (w/v) and evaluated for rheological behavior (G' ranging from 100 to 10,000 Pa), swelling (up to 24 %), retention capacity (stable over 24-30 h), and degradation in proteolytic environments (mass loss ranging from ∼0-11 %, depending on formulation). TA-crosslinked hydrogels showed strong fluid retention and are suitable for high-moisture 3D wound dressings and coating applications. HRP-crosslinked hydrogels demonstrated tunable mechanical properties, shear-thinning behavior, and full recovery post-deformation, making them ideal for use as bioinks in 3D bioprinting and injectable matrices. In vitro assays confirmed cytocompatibility, with viability exceeding 85 %, and successful cell encapsulation and proliferation. Overall, this study presents a versatile SS-based hydrogel platform with potential for various biomedical applications, particularly in skin tissue healing and regeneration.