Concentrated Growth Factors Combined with Lipopolysaccharide Stimulate the In Vitro Regenerative and Osteogenic Activities of Human Dental Pulp Stem Cells by Balancing Inflammation

Abstract

Aim. We investigated the long-term effects of exposure to concentrated growth factors (CGFs) on the regenerative properties of dental pulp stem cells (DPSCs) in the presence and absence of lipopolysaccharide (LPS) as a proinflammatory agent. Methods. DPSCs were cultured with CGF at different concentrations of LPS (0.1, 1, and 10 µg/ml) for 21 days. Then, using MTT and scratch assays, the cell viability and migration were examined. Osteogenic stimulation was evaluated by alkaline phosphatase (ALP) staining and Sirius Red staining, which determined the ALP activity and collagen levels, respectively. The expression levels of osteogenic markers were quantified using the qRT-PCR method. One-way analysis of variance (ANOVA) and Tukey’s HSD test were used to analyze differences between groups. Results. Long-term treatment of DPSCs with CGFs reduced LPS-induced cell death. Moreover, CGF and LPS (1 µg/ml), either in combination or alone, improved the DPSC migratory ability and caused a significant increase in osteogenic stimulation through the upregulation of collagen levels and ALP activity. Additionally, CGFs significantly upregulated RUNX2, DSPP, OCN, and OPN mRNA levels (as osteogenic markers), while LPS (1 µg/ml) only significantly increased OCN overexpression. Conclusion. Our findings are evidence that CGF could be a promising agent to induce dentin-pulp complex healing in long-term chronic inflammation.

The Effects of Mineral Trioxide Aggregate and Second-Generation Autologous Growth Factor on Pulpotomy

“…In addition, Firouzi et al ( 2022) [29] reported that CGF enhanced bone regeneration induced by lipopolysaccharide in cell culture. Similarly, in our study, we observed that CGF regenerated pulpotomyinduced damage.…”

Dental Stem Cells and Lipopolysaccharides: A Concise Review

“…For example, Firouzi et al (2022) used a fibrin scaffold enriched with growth factors to assess the proliferation and differentiation of DPSCs under LPS-induced inflammatory conditions. They observed that DPSCs treated with LPS (1 µg/mL) on the fibrin scaffold promoted the release of pro-inflammatory cytokines such as TNF-α, which supported cell proliferation and migration during dental pulp inflammation [56].…”

“…Therefore, researchers have sought molecules to improve the regenerative process of DPSCs in LPS-induced inflammation. Firouzi et al (2022) observed that the use of concentrated growth factors promoted the release of cytokines such as TNF-α, which positively affected proliferation, migration, and odonto/osteogenic differentiation in DPSCs [56]. Another approach explored involves analyzing the behavior of DPSCs in interaction with bioactive materials to develop strategies in pulp therapy.…”

The Migration and the Fate of Dental Pulp Stem Cells

“…The chemokine receptor CXCR3 (CD183) was found on 30% of the adherent (ADH)-DPSCs [23], associated with neuroinflammatory responses and their potential involvement in homing neural progenitors to sites of brain damage [120]. Another study showed that human-concentrated growth factors (hCGFs) alone and in combination with LPS increased DPSC migration and osteogenic differentiation [121]. A conditioned medium, such as human gingival fibroblast-conditioned medium (hGF-CM), increased the migration, proliferation, cell viability and odontogenic differentiation of DPSCs after H 2 O 2 exposure [44].…”