Abstract
The development of multifunctional, mechanically robust, and sustainable hydrogels from renewable biomaterials has attracted increasing attention for advanced biomedical applications; however, achieving an optimal balance between mechanical stability, biofunctionality, and infection control remains challenging. In this work, collagen (COL) extracted from raw trimming wastes from a tannery is used to fabricate COL/PAA/Fe composite hydrogels via the ammonium persulfate (APS)-initiated polymerization of acrylic acid (AA) coupled with Fe(3+)-mediated coordination cross-linking. The resulting hydrogel network is stabilized by synergistic COL-poly(acrylic acid) (PAA) hydrogen bonding and dynamic Fe(3+)-carboxylate coordination, imparting enhanced mechanical strength and elasticity. The optimized hydrogel exhibited maximum tensile and compressive strengths of ~0.176 MPa at 751% elongation and ~1.945 MPa at a strain of 80%, respectively. In addition, a high ionic conductivity of 4.11 S·m(-1) is achieved, enabling structural integrity under deformation and suitability for flexible electronic interfaces. The prepared hydrogel also displayed rapid autonomous self-healing behavior and substantial antibacterial properties against both Gram-positive and Gram-negative bacteria. Overall, COL is employed herein as a sustainable precursor, highlighting an eco-conscious approach to biomaterial design. This work presents a versatile strategy for producing mechanically stable and biofunctional hydrogels with strong potential for wound dressing, tissue engineering, and injectable biomedical applications.