Injectable Thermo‐Responsive Dentine Matrix Hydrogel for Enhancing Dentine Regeneration

Aim This study aimed to develop an injectable thermo‐responsive composite paste based on digested dentine matrix extract (DDME) for dentine regeneration, with potential applications in vital pulp therapy. Methodology An injectable PLGA–PEG–PLGA/DDME paste was developed and characterized using FTIR. The injectability and self‐curing behavior of the composite were evaluated. Its biocompatibility and odontogenic potential were assessed in vitro using human dental pulp cells (hDPCs). Dentine‐forming capacity was investigated in an in situ rat model. The effect of the paste on protein expression in hDPCs was examined by label‐free proteomic analysis, and the underlying mechanism of DDME‐induced odontogenesis was screened. Data were analyzed using Student's t‐test and one‐way analysis of variance. Results The PLGA–PEG–PLGA/DDME paste exhibited excellent injectability and temperature‐dependent self‐curing. Rheological analysis confirmed shear‐thinning behaviour and enhanced viscoelastic properties compared to Water/DDME controls. PLGA–PEG–PLGA significantly improved the handling characteristics of DDME while preserving its bioactivity. In vitro, the paste supported human dental pulp cell viability, migration and odontogenic differentiation, upregulating RUNX2, DMP‐1, DSPP and ALP, and enhancing mineralized nodule formation. In situ evaluation in a rat dentine defect model demonstrated that the paste promoted the formation of dentine bridges. Proteomic analysis revealed mTOR signalling as a key pathway, and inhibition experiments with rapamycin confirmed its role in mediating DDME‐induced odontogenesis. Conclusions The PLGA‐PEG‐PLGA/DDME composite paste is a promising injectable biomaterial for dentine regeneration, with mTOR modulation offering a potential strategy to optimize outcomes.