| Platelet-rich plasma (PRP) is a source of growth factors that can promote surgical healing. It has been shown to increase the viability and proliferation of osteosarcoma cells (Kanno et al., 2005) and immortalized cell lines (Frechette et al., 2005). However, canine alveolar bone cells were inhibited by concentrated PRP (Choi et al., 2005). The objective of this study was to determine if PRP may inhibit the attachment, viability and differentiation of human alveolar bone cells. A human alveolar bone chip was obtained from a routine oral surgical procedure and explant cultures were harvested after 3-4 weeks of outgrowth in alpha-minimum essential medium supplemented with fetal calf serum (10%). Cells that were either freshly seeded or that had attached for 24 hours were treated with PRP (1%) and (5%) that was obtained from a healthy volunteer, and activated with calcium chloride and thrombin. Treated and untreated cultures were harvested after 1, 24 and 72 hours, and after 1 week. Immunofluorescence microscopy showed that untreated cells attached, spread and proliferated, whereas few cells survived when PRP was added after 24 hours, and none survived the PRP treatment of freshly seeded cells. RT-PCR analysis identified the expression of alkaline phosphatase, bone sialoprotein, collagen and Runx2/Cbfa1 in untreated cultures, that were suppressed following PRP-treatment. These results have demonstrated that platelet-rich plasma can inhibit the viability and differentiation of human alveolar bone cells in both the freshly seeded and confluent states. |
