Fibroblast Growth Factor–2 Regulates the Cell Function of Human Dental Pulp Cells

In vitro and in vivo evaluation of the biocompatibility of a calcium phosphate/poly(lactic-co-glycolic acid) composite

This study assess the effects of bioceramic and poly(lactic-co-glycolic acid) composite (BCP/PLGA) on the viability of cultured macrophages and human dental pulp fibroblasts, and we sought to elucidate the temporal profile of the reaction of pulp capping with a composite of bioceramic of calcium phosphate and biodegradable polymer in the progression of delayed dentine bridge after (30 and 60 days) in vivo. Histological evaluation of inflammatory infiltrate and dentin bridge formation were performed after 30 and 60 days. There was similar progressive fibroblast growth in all groups and the macrophages showed viability. The in vivo study showed that of the three experimental groups: BCP/PLGA composite, BCP and calcium hydroxide (Ca(OH)(2)) dentin bridging was the most prevalent (90 %) in the BCP/PLGA composite after 30 days, mild to moderate inflammatory response was present throughout the pulp after 30 days. After 60 days was observed dentine bridging in 60 % and necrosis in 40 %, in both groups. The results indicate that understanding BCP/PLGA composite is biocompatible and by the best tissue response as compared to calcium hydroxide in direct pulp capping may be important in the mechanism of delayed dentine bridge after 30 and 60 days.

Basic fibroblast growth factor enhances stemness of human stem cells from the apical papilla

INTRODUCTION

Stem cells from the apical papilla (SCAP) are a type of mesenchymal stem cells found in the developing tissue, apical papilla, of immature permanent teeth. Studies have shown that SCAP are likely to be a source of primary odontoblasts that are responsible for the formation of root dentin. Basic fibroblast growth factor (bFGF) is a signaling molecule and pleiotropic growth factor involved in tooth root development, and it promotes proliferation of a variety of cell types. The effects of bFGF on SCAP, however, have not been examined.

METHODS

We investigated the regulatory effects of bFGF on the proliferation and differentiation potential of human SCAP in vitro. Changes in the cell cycle and proliferation, colony-forming unit-fibroblastic formation, alkaline phosphatase (ALP) activity, osteogenic/dentinogenic differentiation, and stem cell gene makers of SCAP, cultured in the presence or absence of bFGF, were evaluated.

RESULTS

Treatment with 5 ng/mL bFGF significantly increased SCAP proliferation and their colony-forming unit-fibroblastic formation efficiency. The growth factor also increased the expression of STRO-1 and the stem cell gene makers Nanog, Oct4, Sox2, and Rex1 in SCAP. In contrast, bFGF reduced the ALP activity, mineral nodule formation, and the expression of ALP, osteocalcin, bone sialoprotein, and dentin sialophosphoprotein. When SCAP cultures were expanded in the presence of bFGF for 1 week, subsequent stimulation of the osteogenic/dentinogenic condition resulted in enhanced differentiation.

CONCLUSIONS

Under certain conditions, bFGF enhances SCAP stemness by up-regulating stem cell gene expression, increasing proliferation ability, and potentiating differentiation potency.

A customized self-assembling peptide hydrogel for dental pulp tissue engineering

Root canal therapy is common practice in dentistry. During this procedure, the inflamed or necrotic dental pulp is removed and replaced with a synthetic material. However, recent research provides evidence that engineering of dental pulp and dentin is possible by using biologically driven approaches. As tissue engineering strategies hold the promise to soon supersede conventional root canal treatment, there is a need for customized scaffolds for stem cell delivery or recruitment. We hypothesize that the incorporation of dental pulp-derived stem cells with bioactive factors into such a scaffold can promote cell proliferation, differentiation, and angiogenesis. In this study, we used a cell adhesive, enzyme-cleavable hydrogel made from self-assembling peptide nanofibers to encapsulate dental pulp stem cells. The growth factors (GFs) fibroblast growth factor basic, transforming growth factor β1, and vascular endothelial growth factor were incorporated into the hydrogel via heparin binding. Release profiles were established, and the influence of GFs on cell morphology and proliferation was assessed to confirm their bioactivity after binding and subsequent release. Cell morphology and spreading in three-dimensional cultures were visualized by using cell tracker and histologic stains. Subcutaneous transplantation of the hydrogel within dentin cylinders into immunocompromised mice led to the formation of a vascularized soft connective tissue similar to dental pulp. These data support the use of this novel biomaterial as a highly promising candidate for future treatment concepts in regenerative endodontics.