Effect of platelet-rich plasma on proliferation of human dermal fibroblasts in vitro

Objective: To evaluate the effects of platelet-rich plasma (PRP) on proliferation of human dermal fibroblasts (hDFbs) in vitro and investigate the mechanism of PRP promoting wound healing. Methods: hDFbs and PRP were separated from a healthy adult donor. PRP was prepared by a double centrifugation technique. In the proliferation experiment a inverted phase contrast microscope was used to observe the growth of cells after treated with different concentrations PRP, such as 0, 12.5%, 25.0%, 50.0% and 100.0%. Immunocytochemistry was used to evaluate the expressions of platelet-derived growth factor (PDGF) treated with 50.0% PRP in different volumes. Fluorescent coloration was used to observe the proliferation of the cells which adhered to the titanium material. Cell cycle of hDFbs was detected by flow cytometry. The cell proliferation was also evaluated by CCK-8 assay. Results: The microscope investigation showed that the number of cells in 100% PRP group was higher than those in other groups. The significant increase in PDGF expression was observed when treated with 30 μL PRP, but the IOD in 10 μL PRP group was higher than that in 20 μL PRP group(836.27 ± 21.15 vs 794.35 ± 30.26, P < 0.05). The fluorescent coloration showed that PRP improved the cell quantity on the material compared with control group. The flow cytometry showed that PRP stimulated the cells to enter the S phage to copy DNA. In the 2nd day after treated with PRP the percent of the cells in S phage in PRP group was higher than that in control group (34.41% is 22.00%, P < 0.05); In the 8th day the percent of the cells in G0G1 phage was higher than that in control group (95.07% vs 89.70%, P < 0.05). The result of CCK-8 showed that the absorbency number in 100.0% PRP group was significantly higher than that in 12.5% group (1.13 ± 0.05 vs 0.75 ± 0.04, P < 0.05) in the 4th day. Conclusion: High concentration PRP has a positive influence on hDFbs proliferation, but it isn't dose-dependent. An appropriate concentration PRP can promote the proliferation of hDFbs.