Tuning the biological scaffolds’ performance by the combination of two antioxidant and antimicrobial chitosan derivatives

Abstract

In this study novel polymeric materials based on chitosan (CS) were synthesized by chemically modifying CS with two bioactive moieties: eugenol and a compound containing a thiazolium group. These modifications aimed to impart antioxidant and antimicrobial properties to the matrix. Additionally, the scaffolds were reinforced with chitin nanowhiskers (Nw) to improve their mechanical strength and stability. Porous three-dimensional scaffolds were fabricated via the freeze-drying process, resulting in highly interconnected pore networks suitable for cell infiltration and nutrient transport. Biological characterization revealed that the incorporation of the two bioactive groups significantly enhanced the antioxidant activity and antimicrobial efficacy against both Gram- positive and Gram-negative bacteria to the scaffolds. Mechanical testing demonstrated that the Nw reinforce ment increased scaffold stiffness and resilience without compromising porosity. In vitro biological assays using fibroblasts showed favorable cytocompatibility and promoted sustained cell proliferation over three weeks. Fluorescence microscopy confirmed fibroblast adhesion and morphological adaptation within the scaffold ar chitecture. Additionally, the scaffolds were evaluated for their immunomodulatory effects using macrophage cultures, revealing a balanced immune response with reduced proinflammatory signaling, which is critical for successful integration and reduced fibrosis in vivo. These results indicate that those are promising candidates for tissue engineering and regenerative medicine applications.