Towards Induction of Angiogenesis in Dental Pulp Stem Cells Using Chitosan-Based Hydrogels Releasing Basic Fibroblast Growth Factor

Abstract

Introduction. Chitosan is a natural biopolymer that attracted enormous attention in biomedical fields. The main components of regenerative endodontic procedures (REPs), as well as tissue engineering, are scaffolds, stem cells, and growth factors. As one of the basic factors in the REPs is maintaining vascularization, this study was aimed at developing basic fibroblast growth factor- (bFGF-) loaded scaffolds and investigating their effects on the angiogenic induction in human dental pulp stem cells (hDPSCs). Methods. Poly (ε-caprolactone) (PCL)/chitosan- (CS-) based highly porous scaffold (PCL/CS) was prepared and evaluated by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) analyses. The adhesion and survival potency of seeded cells were assessed by SEM and MTT assays, respectively. The amount of angiogenic markers was investigated in gene and protein levels by real-time PCR and western blotting assays, respectively. Results. Based on our findings, the SEM and FTIR tests confirmed the appropriate structure of synthesized scaffolds. Besides, the adhesion and survival rate of cells and the levels of VEGFR-2, Tie2, and Angiopoietin-1 genes were increased significantly in the PCL/CS/bFGF group. Also, the western blotting results showed the upregulation of these markers at protein levels, which were considerably higher at the PCL/CS/bFGF group ( $P<0.05$ ). Conclusions. On a more general note, this study demonstrates that the bFGF-loaded PCL/CS scaffolds have the potential to promote angiogenesis of hDPSCs, which could provide vitality of dentin-pulp complex as the initial required factor for regenerative endodontic procedures.