Effects of TGF-β1, PDGF-BB, and IGF-1 on the Rate of Proliferation and Adhesion of a Periodontal Ligament Cell Lineage In Vitro

Abstract

Background: Considering the role of growth factors in periodontal regeneration, the aim of this study was to evaluate the influence of platelet-derived growth factor (PDGF)-BB, insulin-like growth factor (IGF)-1, and transforming growth factor-beta 1(TGF-β1), alone or in combination, on the rate of proliferation and adhesion of periodontal ligament (PDL) cells in vitro.

Methods: After establishment and characterization of a primary culture of PDL cells, 72 culture dishes were plated with 10³ cells distributed among four test groups and a control group. Test groups had PDGF-BB, TGF-β1, IGF-1, or a combination of all three added to the culture medium, whereas the control group received no growth factor. The samples were counted in triplicate 1, 3, 5, and 7 days after seeding. For the adhesion assay, 14 patients provided 30 root fragments distributed among 10 groups: scaling and root planing (SRP), SRP + growth factors, SRP + citric acid plus tetracycline (CA+T), and SRP + (CA+T) + growth factors. The data were evaluated statistically by analysis of variance complemented by Tukey, Dunnett, and Student-Newman-Keuels methods.

Results: Maximum rates of proliferation were observed at day 3 for all groups. TGF-β1 induced a 344.17% ± 58.80% increased proliferation rate over control (P <0.05), followed by the combination (277.5% ± 29.38%), PDGF-BB (238.79% ± 5.79%), and IGF-1 (233.16% ± 19.19%). Groups treated by (CA+T) showed increased numbers of cells attached to root fragments, especially SRP + (CA+T) + combination (13.25 ± 1.79), with significant differences (P <0.05) from groups treated only by SRP.

Conclusion: This combination of growth factors stimulated a mitogenic response and favored the adhesion of PDL cells in vitro, suggesting its possible role in periodontal regeneration.

Keywords: Growth factors; in vitro; periodontal ligament; regeneration; stem cells.