Effects of graphene oxide incorporation via non-covalent interfacial interactions on the properties of small intestinal submucosa

Abstract

To investigate the modifying effect of graphene oxide (GO) on small intestinal submucosa (SIS), GO-SIS biocomposite films were fabricated via a non-covalent coating strategy. Structural analyses confirmed the non-covalent interactions between GO and SIS collagen fibers and the preservation of SIS's native fibrous structure. The GO-SIS biocomposite film showed significantly improved hydrophilicity (contact angle: 71.3 ± 1.0°, p < 0.001; water absorption: 159.00 ± 5.60%, p < 0.01) compared to the SIS film. It also exhibited superior mechanical properties under both dry and wet conditions, with significantly higher tensile strength (dry: 24.46 ± 0.99 MPa; wet: 10.16 ± 0.37 MPa) and elongation at break (dry: 11.41 ± 0.55%; wet: 21.26 ± 0.65%) than the SIS film (p < 0.001 for all comparisons). After in vitro degradation, the GO-SIS biocomposite film showed better morphological stability compared to the SIS film. At 4, 8, 16, 24, 48, and 72 hours, the in vitro degradation of the GO-SIS biocomposite film was significantly slower than that of the SIS film. Furthermore, at 4, 8, 16, and 24 hours, the tensile strength and elongation at break of the degraded GO-SIS biocomposite film were significantly higher than those of the degraded SIS film. Biocompatibility assessment indicated no impact on L929 fibroblast viability or proliferation, along with favorable hemocompatibility. Collectively, the non-covalent incorporation of GO effectively enhances the hydrophilicity and mechanical performance of the GO-SIS biocomposite film and slows down its in vitro degradation, offering a promising strategy for the design of advanced tissue repair materials.