LoB5 unit, Chonnam National University School of Dentistry, 77 Yongbong-Ro, Buk-Gu, Gwangju 500- 757, South Korea.
Curr Pharm Biotechnol. 2012 Jun;13(7):1145-52. doi: 10.2174/138920112800624382.
Platelet concentrates for surgical use are tools of regenerative medicine designed for the local release of platelet growth factors into a surgical or wounded site, in order to stimulate tissue healing or regeneration. Leukocyte content and fibrin architecture are 2 key characteristics of all platelet concentrates and allow to classify these technologies in 4 families, but very little is known about the impact of these 2 parameters on the intrinsic biology of these products. In this demonstration, we highlight some outstanding differences in the growth factor and matrix protein release between 2 families of platelet concentrate: Pure Platelet-Rich Plasma (P-PRP, here the Anitua's PRGF - Preparation Rich in Growth Factors - technique) and Leukocyte- and Platelet-Rich Fibrin (L-PRF, here the Choukroun's method). These 2 families are the extreme opposites in terms of fibrin architecture and leukocyte content. The slow release of 3 key growth factors (Transforming Growth Factor β1 (TGFβ1), Platelet-Derived Growth Factor AB (PDGF-AB) and Vascular Endothelial Growth Factor (VEGF)) and matrix proteins (fibronectin, vitronectin and thrombospondin-1) from the L-PRF and P-PRP gel membranes in culture medium is described and discussed. During 7 days, the L-PRF membranes slowly release significantly larger amounts of all these molecules than the P-PRP gel membranes, and the 2 products display different release patterns. In both platelet concentrates, vitronectin is the sole molecule to be released almost completely after only 4 hours, suggesting that this molecule is not trapped in the fibrin matrix and not produced by the leukocytes. Moreover the P-PRP gel membranes completely dissolve in the culture medium after less than 5 days only, while the L-PRF membranes are still intact after 7 days. This simple demonstration shows that the polymerization and final architecture of the fibrin matrix considerably influence the strength and the growth factor trapping/release potential of the membrane. It also suggests that the leukocyte populations have a strong influence on the release of some growth factors, particularly TGFβ1. Finally, the various platelet concentrates present very different biological characteristics, and an accurate definition and characterization of the different families of product is a key issue for a better understanding and comparison of the reported clinical effects of these surgical adjuvants.
用于外科手术的血小板浓缩物是再生医学工具，旨在将血小板生长因子局部释放到手术或受伤部位，以刺激组织愈合或再生。白细胞含量和纤维蛋白结构是所有血小板浓缩物的两个关键特征，可将这些技术分为 4 个家族，但对于这两个参数对这些产品内在生物学的影响知之甚少。在本演示中，我们突出了两种血小板浓缩物家族之间在生长因子和基质蛋白释放方面的一些显著差异：纯血小板富血浆（P-PRP，这里是 Anitua 的 PRGF-富含生长因子的制备技术）和白细胞及血小板富纤维蛋白（L-PRF，这里是 Choukroun 的方法）。这两个家族在纤维蛋白结构和白细胞含量方面是极端相反的。在培养物中，从 L-PRF 和 P-PRP 凝胶膜缓慢释放 3 种关键生长因子（转化生长因子β1（TGFβ1）、血小板衍生生长因子 AB（PDGF-AB）和血管内皮生长因子（VEGF））和基质蛋白（纤连蛋白、 vitronectin 和 thrombospondin-1）进行了描述和讨论。在 7 天内，L-PRF 膜缓慢释放的所有这些分子的量明显大于 P-PRP 凝胶膜，并且两种产品显示出不同的释放模式。在这两种血小板浓缩物中，vitronectin 是唯一在仅 4 小时后几乎完全释放的分子，这表明该分子未被困在纤维蛋白基质中，也不是由白细胞产生的。此外，P-PRP 凝胶膜在不到 5 天内完全溶解在培养基中，而 L-PRF 膜在 7 天后仍完好无损。这个简单的演示表明，纤维蛋白基质的聚合和最终结构极大地影响了膜的强度和生长因子捕获/释放潜力。它还表明，白细胞群对某些生长因子（尤其是 TGFβ1）的释放有很强的影响。最后，各种血小板浓缩物表现出非常不同的生物学特性，因此对不同产品家族的准确定义和表征是更好地理解和比较这些外科辅助剂的临床效果的关键问题。
