Ti₃C₂Tx MXene Potentiates PSAT1-Mediated Osteogenesis Through miR-665/GSK-3β/β-Catenin Axis to Counteract...

Inflammatory signaling-induced stem cell dysfunction severely impairs bone regeneration. This study aimed to develop a combinatorial strategy using Ti₃C₂T_x MXene scaffolds and PSAT1-engineered dental pulp stem cells (oe-PSAT1 DPSCs) to counteract inflammation-mediated osteogenic suppression.

Dental pulp stem cells (DPSCs) were treated with TNF-α to simulate an inflammatory microenvironment. miR-665 expression and its targeting relationship with PSAT1 were analyzed via qRT-PCR, dual-luciferase reporter assay, and Western blot. The role of the miR-665/PSAT1/GSK-3β/β-catenin axis in osteogenic differentiation was evaluated using ALP activity, alizarin red staining, and immunofluorescence. Ti₃C₂T_x MXene was synthesized and characterized, and its effects on ROS scavenging and osteogenesis were assessed in vitro. In vivo efficacy was validated using a rat calvarial defect model with micro-CT, histological staining, and immunohistochemistry.

TNF-α stimulation upregulated miR-665, which directly targeted PSAT1 and inhibited the GSK-3β/β-catenin pathway, suppressing DPSCs osteogenic differentiation. PSAT1 overexpression rescued this suppression. Ti₃C₂T_x MXene scavenged ROS, enhanced calcium-dependent mineralization, and synergized with oe-PSAT1 DPSCs to amplify β-catenin activation. In rat models, the Ti₃C₂T_x MXene /oe-PSAT1 DPSCs combination achieved superior bone defect closure (higher BV/TV, Tb. Th, and mature collagen deposition) compared to Ti₃C₂T_x MXene alone.

This study identifies the miR-665/PSAT1/GSK-3β/β-catenin axis as a key regulator of inflammatory osteogenesis. The Ti₃C₂T_x MXene/oe-PSAT1 DPSCs strategy concurrently neutralizes oxidative stress and activates osteogenic signaling, providing a translatable platform for inflammatory bone regeneration.