The relationship between platelet adhesion on surfaces and the structure versus the amount of adsorbed fibrinogen.
The relationship between platelet adhesion on surfaces and the structure versus the amount of adsorbed fibrinogen.
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DOI：
10.1016/j.biomaterials.2009.10.008
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发表时间：
2010-02
期刊：
影响因子：
14
通讯作者：
Latour, Robert A.
中科院分区：
文献类型：
--
作者：
Sivaraman, Balakrishnan;Latour, Robert A.
虽然人们普遍认为血小板粘附在生物材料表面与吸附的纤维蛋白原（Fg）有关，但血小板粘附是与该蛋白的吸附量有关还是与该蛋白的吸附构象有关仍存在争议。为了解决这个问题，我们设计了一系列血小板粘附研究来明确分离这两个因素，从而使我们能够明确地确定是吸附Fg的数量还是构象介导了血小板反应。Fg在不同的溶液浓度下都能被吸附在不同的表面化学物质上，吸附Fg的量和构象分别由吸光度和圆二色（CD）光谱偏振法测定。采用乳酸脱氢酶（LDH）测定和扫描电镜（SEM）观察血小板粘附反应。我们的研究结果表明，血小板粘附与Fg吸附诱导的展开程度密切相关（r2 = 0.96），与Fg吸附量基本无关（r2 = 0.04）。使用RGDS肽的血小板受体抑制剂研究仅减少了约50%的血小板粘附，扫描电镜结果显示，与未阻断的血小板相比，RGDS阻断后的粘附血小板更圆润，丝状伪足延伸最小。这些结果提供了明确的证据，证明吸附Fg的构象是血小板粘附的关键决定因素，而不是吸附Fg的数量，吸附诱导的展开可能暴露Fg中两种明显不同类型的血小板结合位点；一种是单独诱导血小板粘附另一种是同时诱导血小板粘附和活化。
While platelet adhesion to biomaterial surfaces is widely recognized to be related to adsorbed fibrinogen (Fg), it has remained controversial whether platelet adhesion is in response to the adsorbed amount or the adsorbed conformation of this protein. To address this issue, we designed a series of platelet adhesion studies to clearly separate these two factors, thus enabling us to definitively determine whether it is the amount or the conformation of adsorbed Fg that mediates platelet response. Fg was adsorbed to a broad range of surface chemistries from a wide range of solution concentrations, with the amount and conformation of adsorbed Fg determined by absorbance and circular dichroism (CD) spectropolarimetry, respectively. Platelet adhesion response was determined by lactate dehydrogenase (LDH) assay and scanning electron microscopy (SEM). Our results show that platelet adhesion is strongly correlated with the degree of adsorption-induced unfolding of Fg (r2 = 0.96) with essentially no correlation with the amount of Fg adsorbed (r2 = 0.04). Platelet receptor inhibitor studies using an RGDS peptide reduced platelet adhesion by only about 50%, and SEM results show that adherent platelets after RGDS blocking were much more rounded with minimal extended filopodia compared with the unblocked platelets. These results provide definitive proof that the conformation of adsorbed Fg is the critical determinant of platelet adhesion, not the amount of Fg adsorbed, with adsorption-induced unfolding potentially exposing two distinctly different types of platelet binding sites in Fg; one that induces platelet adhesion alone and one that induces both platelet adhesion and activation.
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DOI：
10.1021/la8036814
发表时间：
2009-03-03
期刊：
Langmuir : the ACS journal of surfaces and colloids
影响因子：
--
作者：
Sivaraman B;Fears KP;Latour RA
通讯作者：
Latour RA
影响因子：
15
作者：
Sigal, GB;Mrksich, M;Whitesides, GM
通讯作者：
Whitesides, GM
影响因子：
14.8
作者：
Greenfield, Norma J.
通讯作者：
Greenfield, Norma J.
DOI：
10.1021/la901885d
发表时间：
2009-08-18
期刊：
Langmuir : the ACS journal of surfaces and colloids
影响因子：
--
作者：
Fears KP;Sivaraman B;Powell GL;Wu Y;Latour RA
通讯作者：
Latour RA
影响因子：
14
作者：
Abraham, GA;de Queiroz, AAA;San Román, JS
通讯作者：
San Román, JS