The Effects of Two rhPDGF-BB Applications on Periodontal Ligament Cell’s Proliferation and VEGF Expression

Abstract

Background: Platelet derived growth factor (PDGF) has been shown since the late 1980s to play a major role in periodontal regeneration. PDGF has five isoforms and the isoform PDGF-BB has been found to be the most effective. Animal studies evaluating release kinetics of purified recombinant human platelet-derived growth factor (rh-PDGF-BB), demonstrated that 90% of rh-PDGF-BB was depleted from sites within 72 hours after implantation. Thus, the aim of this in-vitro study was to evaluate the effects of two rhPDGF-BB applications on periodontal ligament fibroblasts proliferation and VEGF expression. Materials & Methods: Periodontal ligament (PDL) cells were seeded in multiple 6 well plates and split into 3 groups. Group 1 served as a control that received no rh-PDGF-BB. Group 2 was given an initial dose of 10 ng/ml rhPDGF-BB on day 1 and none on day 3. Group 3 received a dose of 10 ng/ml rhPDGF-BB on day 1 and a second dose on day 3. On day 3, half of the plates were stopped and media collected was used for LDH, WST-1 and VEGF ELISA analysis for evaluation of VEGF expression, cellular proliferation and cytotoxicity. Plain media was then added to groups 1 and 2 while group 3 received media with rh-PDGF-BB. On day 6, the collected media was used for ELISA, WST-1 and LDH assays. Results: PDL cell proliferation was not significantly different between any group studied (p=0.689). VEGF expression was increased in group 2 and 3 on day 3 compared to group 1 (p=0.005). There was no difference between groups 1 and 2 on day 6 (p=0.977). Conclusion: The addition of rhPDGF-BB to PDL cells did not increase proliferation at any time point. A single application of rhPDGF-BB increased the expression of VEGF from PDL cells; however, an additional application did not significantly increase the expression of VEGF.