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

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.

The Antimicrobial, Antioxidative, and Anti-Inflammatory Effects of Polycaprolactone/Gelatin Scaffolds Containing Chrysin for Regenerative Endodontic Purposes.

The appropriate endodontic material should eliminate the infection and inflammation to provide a situation for regeneration and healing of pulp tissue besides biomineralization. Chrysin is one of the active ingredients of plant flavonoids, which has significant anti-inflammatory and antimicrobial properties. In the present study, this natural substance was evaluated for antioxidant, anti-inflammatory, and mineralization properties on dental pulp stem cells (DPSCs). SEM, FTIR, and TGA tests were used to determine the successful synthesize of chrysin-loaded scaffolds. The antimicrobial effects of the synthesized scaffold against Acinetobacter baumannii, Pseudomonas aeruginosa, Staphylococcus aureus, and Enterococcus faecalis were assessed by the agar diffusion test and live/dead assay. The proliferation of DPSCs on these scaffolds was determined by the MTT assay, DAPI staining, and DNA extraction. Moreover, the antioxidant and anti-inflammation activity of chrysin-loaded scaffolds on inflamed DPSCs was evaluated. Alkaline phosphatase activity and Alizarin Red S Stain tests were done to evaluate the mineralization of DPSCs seeded on these scaffolds. The chrysin-loaded scaffolds reported antimicrobial effects against evaluated bacterial strains. The proliferation of DPSCs seeded on these scaffolds was increased significantly (p < 0.05). The TNFα and DCF levels in inflamed DPSCs showed a significant decrease in the presence of chrysin-loaded scaffolds (p < 0.05). The ALP activity and formation of mineralized nodules of DPSCs on these scaffolds were significantly increased compared with the control group (p < 0.05). These results indicated that chrysin as an ancient therapeutic agent can accelerate the healing and regeneration of damaged pulp tissue, and this active ingredient can be a potential natural substance for regenerative endodontic procedures.