Fufa Duretti, Shealy Blake, Jacobson May, Kevy Sherwin, Murray Martha M
Department of Orthopaedic Surgery, Harvard Medical School, Children's Hospital of Boston, Boston, MA 02115, USA.
J Oral Maxillofac Surg. 2008 Apr;66(4):684-90. doi: 10.1016/j.joms.2007.06.635.
Platelet-rich plasma (PRP) has recently been found to be a useful delivery system for growth factors important to oral tissue healing. But application of PRP in a liquid form to a wound site within the oral cavity can be complicated by significant loss of the PRP into the surrounding oral space unless gelation through the clotting mechanism is accomplished. Gelation is currently accomplished using bovine thrombin; however, rare but serious complications of this method have led to the search for alternative clotting mechanisms, including the use of soluble collagen as a clotting activator. In this work, our hypothesis was that soluble type I collagen would be as effective as bovine thrombin in causing clotting of the PRP and stimulating growth factor release from the platelets and granulocytes.
PRP from human donors was clotted using type I collagen or bovine thrombin. Clot retraction was determined by measuring clot diameters over time. The release of platelet-derived growth factor (PDGF)-AB, transforming growth factor (TGF)-beta1, and vascular endothelial growth factor (VEGF) from both types of clots was measured over 10 days using enzyme-linked immunosorbent assasy.
Clots formed using type I collagen exhibited far less retraction than those formed with bovine thrombin. Bovine thrombin and type I collagen stimulated similar release of PDGF-AB and VEGF between 1 and 10 days; however, thrombin activation resulted in a greater release of TGF-beta1 during the first 5 days after activation.
The use of type I collagen to activate clotting of PRP may be a safe and effective alternative to bovine thrombin. The use of collagen results in less clot retraction and equal release of PDGF-AB and VEGF compared with currently available methods of clot activation.
富含血小板血浆（PRP）最近被发现是一种用于输送对口腔组织愈合至关重要的生长因子的有用系统。但是，除非通过凝血机制实现凝胶化，否则将液态PRP应用于口腔内的伤口部位时，PRP会大量流失到周围口腔空间中，这可能会使情况变得复杂。目前使用牛凝血酶来实现凝胶化；然而，这种方法虽罕见但会引发严重并发症，这促使人们寻找替代的凝血机制，包括使用可溶性胶原蛋白作为凝血激活剂。在本研究中，我们的假设是可溶性I型胶原蛋白在促使PRP凝血以及刺激血小板和粒细胞释放生长因子方面与牛凝血酶一样有效。
使用I型胶原蛋白或牛凝血酶使来自人类供体的PRP发生凝血。通过随时间测量凝块直径来确定凝块收缩情况。使用酶联免疫吸附测定法在10天内测量两种凝块中血小板衍生生长因子（PDGF）-AB、转化生长因子（TGF）-β1和血管内皮生长因子（VEGF）的释放情况。
使用I型胶原蛋白形成的凝块收缩程度远低于使用牛凝血酶形成的凝块。在第1天至第10天期间，牛凝血酶和I型胶原蛋白刺激产生的PDGF-AB和VEGF释放量相似；然而，凝血酶激活在激活后的前5天导致TGF-β1释放量更大。
使用I型胶原蛋白激活PRP凝血可能是牛凝血酶的一种安全有效的替代方法。与目前可用的凝血激活方法相比，使用胶原蛋白导致凝块收缩较小，且PDGF-AB和VEGF释放量相同。
