Platelet-rich plasma enhances human osteoblast-like cell proliferation and differentiation

Platelet-rich plasma enhances human osteoblast-like cell proliferation and differentiation
March 2005
Takahiro Kanno, DDS * *
Tetsu Takahashi, DDS, PhD ÇƒÜ
Toshiyuki Tsujisawa, MS Çƒ?
Wataru Ariyoshi, DDS ¨?
Tatsuji Nishihara, DDS, PhD ?
Journal of Oral and Maxillofacial Surgery Online
Abstract
Purpose Platelet-rich plasma (PRP) is widely used to promote tissue healing. However, there is no concrete evidence for the biological effects of PRP. This study evaluated the biological effects of PRP on the proliferation and differentiation of 2 human osteoblast-like cell lines.
Materials and methods Human osteosarcoma cell lines HOS and SaOS-2 were used in this study. PRP was prepared from freshly drawn human venous blood containing a large number of platelets. The MTT assay was used to examine the effects of PRP on osteoblast viability. To evaluate the growth and differentiation, alkaline phosphatase activity was assessed and the expression of procollagen type I, osteopontin, and osteoprotegerin mRNA was measured using semiquantitative reverse transcriptase-polymerase chain reaction. Further, core binding factor alpha 1 (cbfa1/Runx2/AML3/PebpaA), a critical regulator of osteoblast differentiation, was also determined.
Results The administration of PRP enhanced the viability of HOS and SaOS-2 cells in a dose-dependent manner. Alkaline phosphatase activity was suppressed during the cell growth phase, but was strongly enhanced when the cells reached confluence. Semiquantitative reverse-transcription polymerase chain reaction analysis showed that PRP enhanced the levels of procollagen type I, osteopontin, osteoprotegerin, and core binding factor alpha 1 (cbfa1) mRNA.
Conclusion These results suggest that PRP has a favorable effect on human osteoblast-like cells, and acts both to enhance bone regeneration and as an activator in wound healing.
Platelet-rich plasma (PRP) is an autologous source of various growth factors that is obtained by sequestering and concentrating freshly drawn venous blood. Its use to promote tissue healing has become popular in oral and maxillofacial surgery. Platelets are very important in wound healing because they promote the initial coagulation at wounds and also release many wound healing growth factors.1ÇƒÏ3 Tayapongsak et al4 reported that using autologous fibrin adhesive with cancellous bone enhanced osteoconduction by means of the fibrin network and that it was useful for promoting adhesion.5 In 1998, Marx et al6 wrote of the remarkable clinical benefit of applying autologous concentrated platelet gel (a form of PRP) in oral and maxillofacial reconstructive surgery. Platelets release various growth factors, such as platelet-derived growth factor, transforming growth factors ?¸1 and ?¸2 (TGF-?¸1 and -?¸2), vascular endothelial growth factor, basic fibroblast growth factor, and platelet activating factor-4.7ÇƒÏ9
Recently, PRP has been applied clinically to facilitate bone and tissue healing.10ÇƒÏ13 Some trials have shown that using PRP during the placement of dental implants promotes osseointegration and bone regeneration.17,18 Furthermore, the use of PRP in maxillofacial reconstruction and periodontal regenerative therapy has drawn considerable attention.6,11,12
Preliminary studies have shown the favorable effects of PRP in bone regeneration, as evaluated using radiographic and histomorphometric means. Marx15 reported that PRP enhanced the bone maturation rate and bone density 1.62- to 2.16-fold using clinical, histologic, and histomorphometric methods, suggesting its efficacy for treating large mandibular continuity defects. However, only a few pilot studies have evaluated the effect of PRP on bone healing, including studies of rabbit cranial defects16 and dental implants in miniature pigs,17 and the results are still equivocal and conflicting.11,18
Because scientific evidence assessing the validity of using PRP in dental, oral, and maxillofacial procedures is urgently required, this study investigated the effects of PRP on the proliferation and differentiation of human osteoblast-like cells. While it is now accepted that the transcription factor core binding factor alpha 1 (cbfa1/Runx2/AML3/PebpaA) is a critical regulator of osteoblast differentiation, the effect of PRP on the expression of cbfa1 mRNA in osteoblasts was examined.19 This study evaluated the biological effects of PRP at the molecular level in an in vitro model.
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