van den Dolder Juliette, Mooren Rob, Vloon Annelies P G, Stoelinga Paul J W, Jansen John A
Department of Periodontology and Biomaterials, Radboud University Nijmegen Medical Center, Nijmegen, the Netherlands.
Tissue Eng. 2006 Nov;12(11):3067-73. doi: 10.1089/ten.2006.12.3067.
Platelet-rich plasma (PRP) is a new application of tissue engineering and a developing area for clinicians and researchers. It is a storage vehicle of growth factors (GFs) such as platelet-derived growth factor (PDGF)- AA, -BB, -AB; transforming growth factor (TGF)-beta1 and -2; platelet-derived epidermal growth factor (PDEGF); platelet-derived angiogenesis factor (PDAF); insulin growth factor-1 (IGF-1); and platelet factor- 4 (PF-4), which are known to influence bone regeneration. However, animal and clinical studies reveal different results with the use of PRP and its effect on bone healing. This could be due to the differences between species, that is, differences between species in GF concentrations or variation in presence of GFs between the various PRPs. In this study, rat bone marrow cells were cultured in PRP-coated wells or in uncoated wells for 16 days in osteogenic medium, and analyzed on cell growth (DNA content) and cell differentiation (alkaline phosphatase [ALP] activity, calcium content, scanning electron microscopy, and QPCR). The concentrations of TGF-beta1, PDGF-AA, PDGF-AB, and PDGF-BB in rat, goat, and human PRP were subsequently determined. The results showed that PRP stimulated initial cell growth and had no effect on ALP activity. The calcium measurements showed a significant increase in calcium at days 8, 12, and 16. The real-time PCR results showed that PRP upregulated osteocalcin at day 1 and collagen type I at day 8. Overall, the immunoassays revealed that human PRP contained higher concentrations of growth factors per platelet compared to rat and goat PRP. Goat PRP showed higher concentrations of growth factors per platelet as compared to rat PRP except for PDGF-BB, which had a higher concentration in rat PRP. TGF-beta1 was the most abundant growth factor in all 3 PRPs. On the basis of our results, we conclude that platelet-rich plasma contains osteo-inductive growth factors, which are probably species related. However, we cannot generalize the results because of large intraspecies variations. Further, we conclude that rat PRP gel stimulates initial growth and differentiation of rat bone marrow cells in vitro.
富血小板血浆（PRP）是组织工程学的一项新应用，也是临床医生和研究人员关注的一个发展领域。它是诸如血小板衍生生长因子（PDGF）-AA、-BB、-AB；转化生长因子（TGF）-β1和-2；血小板衍生表皮生长因子（PDEGF）；血小板衍生血管生成因子（PDAF）；胰岛素生长因子-1（IGF-1）；以及血小板因子-4（PF-4）等生长因子（GFs）的储存载体，已知这些生长因子会影响骨再生。然而，动物和临床研究显示，使用PRP及其对骨愈合的影响结果各异。这可能是由于物种之间的差异，即不同物种之间生长因子浓度的差异，或者不同PRP中生长因子存在情况的变化。在本研究中，将大鼠骨髓细胞在PRP包被的孔或未包被的孔中于成骨培养基中培养16天，并对细胞生长（DNA含量）和细胞分化（碱性磷酸酶[ALP]活性、钙含量、扫描电子显微镜和定量聚合酶链反应）进行分析。随后测定了大鼠、山羊和人PRP中TGF-β1、PDGF-AA、PDGF-AB和PDGF-BB的浓度。结果表明，PRP刺激细胞初始生长，对ALP活性无影响。钙含量测定显示在第8、12和16天时钙含量显著增加。实时聚合酶链反应结果显示，PRP在第1天上调骨钙素，在第8天上调I型胶原。总体而言，免疫测定显示，与大鼠和山羊PRP相比，人PRP每个血小板所含生长因子浓度更高。与大鼠PRP相比，山羊PRP每个血小板所含生长因子浓度更高，但PDGF-BB除外，其在大鼠PRP中的浓度更高。TGF-β1是所有三种PRP中含量最丰富的生长因子。基于我们的结果，我们得出结论，富血小板血浆含有骨诱导生长因子，这些因子可能与物种有关。然而，由于种内差异较大，我们不能将结果一概而论。此外，我们得出结论，大鼠PRP凝胶在体外刺激大鼠骨髓细胞的初始生长和分化。
