Engineering Crosslinker‐Free Sericin–Gelatin Hydrogels With Tunable Rheology for <scp>3D</scp> Printing Applications

ABSTRACT Hydrogels can be processed by 3D printing to manufacture tailor made structures, broadening their vast range of applications. In this study, we developed crosslinker‐free hydrogels for 3D printing using different sericin‐to‐gelatin ratios. The rheological assessment confirmed pronounced shear‐thinning behavior in all samples, with a decrease in viscosity as shear rate increased, establishing relevant composition–rheology relationships relevant for extrusion‐based additive manufacturing. All printed samples showed shape fidelity, and those with the highest sericin content presented enhanced stability in phosphate‐buffered saline solution, as revealed by swelling and degradation studies. These trends arise from interactions between gelatin and sericin, as shown by infrared spectra, which showed changes in band intensity and frequency consistent with strengthened hydrogen‐bond networks. This results from the polar nature of both proteins, as revealed by amino acid composition analysis. Additionally, cytotoxicity assays revealed that the hydrogels are non‐cytotoxic. In summary, the combination of sericin with gelatin resulted in homogenous hydrogels suitable for 3D printing, highlighting the potential of sericin as a sustainable modifier to tailor the viscoelastic, structural and functional characteristics of biopolymer networks. The addition of sericin also led to more stable samples with lower swelling, enabling more controlled release of bioactive substances for biomedical applications.