Effect of tube cooling on the osteogenic activity of concentrated platelet-rich fibrin in human periodontal ligament cells.

OBJECTIVE: To compare the effect of concentrated platelet-rich fibrin (C-PRF) immediately after collection to C-PRF kept in a cooling device for about 90 min on the proliferation, osteogenic differentiation, and mineralization in human periodontal ligament cells (hPDLCs). METHODS: Ten milliliters of blood without anticoagulants was collected in two tubes from 12 systemically healthy male volunteers and subjected to centrifugation at 700 RCF (relative centrifugal force)-max for 8 min for the test groups. C-PRF was collected immediately from the tubes of the first group, whereas in the second group, the tube was maintained at 4°C prior to blood collection and centrifugation, and following centrifugation, it was returned to a cooling device at 4°C for 90 min. This was then co-cultured with hPDLCs for 21 days. Cell viability and alkaline phosphatase levels were assessed on days 1, 7, 14, and 21. At the end of 21 days, Alizarin Red staining was done to assess the formation of mineralized nodules. All outcome assessments were conducted in three groups: C-PRF, cooled C-PRF, and a control group comprising hPDLCs cultured in an osteogenic basal culture medium without C-PRF and without any intervention. STATISTICAL ANALYSIS: Linear mixed-effects models were used to analyze values across groups and time points. RESULTS: Both the C-PRF group and cooled C-PRF group demonstrated significantly higher cell proliferation and alkaline phosphatase levels than the control group at day 7 and day 14. However, there was no statistically significant difference between the C-PRF and cooled C-PRF groups when compared for cell proliferation and alkaline phosphatase production at days 1, 7, 14, and 21 (p > 0.05). At the end of 21 days, both groups demonstrated significantly higher mineralization than the control group (p < 0.05); however, there was no difference between the C-PRF and the cooled C-PRF groups. CONCLUSION: Usage of C-PRF after storage at 4°C up to 90 min does not significantly alter cell proliferation, alkaline phosphatase production, and mineralized nodule formation compared with conventional C-PRF in hPDLCs.