Decellularized Dental Pulp Matrix Hydrogel Promotes Functional Endodontic Regeneration In Situ

An appropriate scaffold material is crucial for the success of tissue-engineered regenerative endodontic therapies. In this study, a porcine-derived decellularized dental pulp matrix hydrogel (pDDPM-G) was prepared and employed as the primary scaffold for in situ regeneration of the pulp-dentine complex in beagle dogs.

In the orthotopic pulp regeneration model, pDDPM-G was either directly injected into the root canals of canine teeth (with or without blood induction) or used as a carrier for transplantation of dental pulp stem cells (DPSCs). Collagen type I (COL I) injection (with or without blood induction) and revascularization therapy (blood induction alone) served as controls. Computed tomography images were acquired before and after surgery. Histological and immunofluorescence analyses were conducted for in vivo characterization at 14 and 90 days post-surgery, respectively.

The experimental results showed that the application of pDDPM-G was critical to all three regenerative endodontic procedures, whether combined with DPSC transplantation, used with blood induction (BI), or applied alone for cell homing. Integration of pDDPM-G reduced the extent of intracanal calcification compared with conventional revascularization therapy (BI) alone. Furthermore, expression of all representative proteins, including odontoblast-like (DSPP and DMP1), angiogenic (CD31 and KDR) and neurogenic (MAP2 and TUJ1) markers, was much higher in all pDDPM-G-containing groups than in the BI+COL I, COL I and BI groups.

This study demonstrated the significance of pDDPM-G in functional endodontic regeneration using an orthotopic canine model. It was found that the use of pDDPM-G was not only beneficial for root development but also facilitated pulp-like tissue morphogenesis, dentinogenesis, angiogenesis and neurogenesis, thereby reconstructing hierarchically distributed functional pulp-dentine complexes.