A graphene oxide/niobium carbide MXene composite-based functional nanocomposite scaffold for artificial corneas†

Artificial corneas offer the only hope to end-stage corneal disease patients. A highly desirable artificial cornea requires high mechanical strength, good biocompatibility, and sufficient durability to withstand hostile environments and possesses specific biological activities. This study reports the physical characteristics, cytocompatibility, and biocompatibility of graphene oxide and niobium carbide MXene (GO/Nb₂C) nanocomposites used in normal rabbit corneas and a corneal alkali burn model. Nanoindentation and long-term corrosion assays in combination with atomic force and scanning electron microscopy were used to study mechanical properties and corrosion resistance. In vitro biocompatibility was evaluated based on the survival, proliferation, and attachment of human corneal stromal cells. In vivo stability and host tissue responses were determined using GO/Nb₂C scaffolds implanted in rabbit corneas and in an in vivo corneal alkali burn model. Fibrosis indices Hsp47, FN, and a-SMA were negative. Furthermore, IL-2 and IL-6 were downregulated, along with oxidative stress indices in the rabbit cornea after implanting GO/Nb₂C scaffolds. In the in vivo corneal alkali burns model, Immunofluorescence (IF)  indicated that the GO/Nb₂C scaffolds decreased CD11b expression around the surgical area. The GO/Nb₂C scaffolds have significantly high biocompatibility with biological activity, safety, efficacy, antioxidative stress, and anti-inflammatory properties. This promising bioactivity of the corneal scaffold provides novel strategies for constructing a functional scaffold of artificial corneas.