Multilayered Titanium Carbide MXene Film for Guided Bone Regeneration

Purpose: MXenes are two-dimensional (2D) materials that are increasingly being applied in biomedical fields. This is ascribed to their good physiochemical properties, unique structure and high biological compatibility. However, the osteogenic activity and suitability of these materials for bone tissue engineering are not clearly understood. Thus, the aim of this study is to evaluate the biocompatibility, osteoinductivity and guided bone regeneration ability of [Ti.sub.3][C.sub.2][T.sub.x] MXene in vitro and in vivo. Methods: Multilayered [Ti.sub.3][C.sub.2][T.sub.x] MXene films were prepared and characterized by XRD and SEM. In vitro experiments were performed to evaluate the effect of MXene films on cell adhesion and morphology with SEM and fluorescence microscopy. The cytotoxicity of MXene films was detected with the Live/Dead double-staining tests. The EdU assay was employed to evaluate cell proliferation on MXene films and ALP activity was tested to determine the effect of the films on osteogenic differentiation in vitro. The mRNA expression of osteogenic differentiation-related markers was measured using qRT-PCR. In vivo animal studies were performed in which the MXene films were implanted subcutaneously in rats to evaluate biocompatibility and host tissue response in vivo. In addition, a rat calvarial defect model was established to examine the bone regeneration performance of the [Ti.sub.3][C.sub.2][T.sub.x] MXene films. The specimens were analyzed with micro-CT evaluation and histological tests. Results: The XRD and SEM analyses revealed that the [Ti.sub.3][C.sub.2][T.sub.x] MXene film was successfully synthesized. The cellular experiments showed that MXene films were highly cytocompatible and enhanced osteogenic differentiation in vitro. When implanted into subcutaneous sites and calvarial defect sites in rats, MXene films showed good biocompatibility, osteoinductivity and bone regeneration activity in vivo. Conclusion: In summary, this study presents new applications of MXenes in bone tissue engineering and in guided bone regeneration therapy. Keywords: [Ti.sub.3][C.sub.2][T.sub.x], bone tissue engineering, GBR, osteoinductivity, biocompatibility