Exploring Xanthan Gum as a Plasticizer in Silk Fibroin/Gelatin Films: Toward Self‐Assemblies, Robust, and Cytocompatible Structures

Protein-based films resemble the ECM matrix and facilitate tissue regeneration, which makes them suitable polymers for biomedical applications. However, they often lack flexibility, which reduces their utility. The addition of plasticizers reduces the molecular interactions responsible for brittleness of these biopolymers, thereby rendering them flexible. This study explores the use of xanthan gum (XG) as a plasticizer in silk fibroin (SF) and gelatin (G) films, presenting a novel approach to developing a flexible matrix. The gelation kinetic studies assess the evolution of storage modulus (G') as a function of time to determine the structural network formation. The addition of XG molecules improves the matrix's flexibility and elongation, as confirmed using tensile strength. Raman spectra confirm β-sheet formation, while X-ray diffraction shows structural changes. The cytocompatibility of developed films is assessed using the MTT assay, while cell adhesion and morphology are studied using SEM, and live/dead assay with L929 cells. Furthermore, ROS production is assessed using the DCFH assay. Immunocompatibility of the films is evaluated by analyzing TNF-α and IL-6 genes in RAW 264.7 cells. The hemolysis of developed films is assessed to evaluate their blood compatibility. The SF/G/XG films showed transparency, stability, and enhanced mechanical properties, making them suitable for biomedical applications.