Design of Extracorporeal Specific Antibody Filters

描述（由申请人提供）： 拟议的研究将开发和研究特异性抗体过滤器（SAF），用于体外捕获引起超急性器官排斥反应的抗A血型抗体（Abs）。抗A抗体是ABO血型不合移植的最具临床意义的障碍。SAF由中空纤维膜组成，A抗原（Ag）附着在纤维内腔表面。在SAF的全血灌注期间，靶向Ab与Ag结合并被去除。我们将建立SAF的设计和操作原则，并利用这些原则开发一种SAF，可以从循环血液中捕获临床有用水平的抗A。本研究的具体目的是：1。合成三糖和相关四糖A抗原。使用这些，我们将使用几种合成的Ag结合物来测试膜，并评估其与Ag类型和组成相关的Ab结合相互作用和功能能力，包括使用间隔分子。我们将用最有前途的合成Ag缀合物制造mini-SAF模块，并且我们将验证它们的Ab结合特性，并在实验台灌注实验中评估初步的血液生物相容性。2.使用台式灌注回路评估SAF模块中抗体捕获的传质特征。我们将研究Ab清除率对关键操作参数的依赖性，包括纤维上的Ag类型和负载、内腔流速、入口抗体浓度、超滤速率和红细胞的影响。我们将比较实验间隙SAF纤维中的Ab运输的理论模拟，以获得SAF性能的预测模型，以帮助SAF的设计，开发和操作。3.设计和制造SAF模块，能够将全身血容量中的正常抗A水平降低至ABO不相容移植的可接受临床目标。对这些“临床”SAF的Ab捕获进行体外评价。进行急性小牛实验，以评估“临床”SAF原型的体内抗A捕获和总体体内生物相容性。虽然抗-A去除是这项资助的主题，但拟议的工作将为针对其他致病性抗体（包括抗-B血型抗体）的有效SAF设备的设计和操作提供科学框架，这是一种临床意义不大但仍然重要的ABO不相容移植障碍。

DESCRIPTION (provided by applicant): The proposed research will develop and study specific antibody filters (SAFs) for extracorporeal capture of anti-A blood group antibodies (Abs) causing hyperacute organ rejection. Recipient anti-A represents the most clinically significant impediment to ABO-incompatible transplantation. The SAFs will consist of hollow fiber membranes with A antigens (Ags) attached to the fiber lumenal surfaces. The targeted Abs bind to the Ags during whole blood perfusion of the SAF and are removed. We will establish design and operational principles for the SAF and exploit these to develop a SAF that can capture clinically useful levels of anti-A from circulating blood. The specific aims of the proposed research are to: 1. Synthesize trisaccharide and related tetrasaccharide A antigens. Using these we will immobilize several synthetic Ag conjugates to test membranes and assess their Ab binding interactions and functional capacity as related to Ag type and composition, including use of spacer molecules. We will fabricate mini-SAF modules with the most promising synthetic Ag conjugates, and we will verify their Ab binding characteristics and assess preliminary blood biocompatibility in bench perfusion experiments. 2. Evaluate the mass transfer characteristics of Ab capture in SAF modules using a bench-top perfusion loop. We will study the dependence of Ab clearance on key operating parameters, including Ag type and loading on fibers, lumenal flow rate, inlet antibody concentration, ultrafiltration rate, and the effects of red cells. We will compare experimental clearances to theoretical simulations of Ab transport in SAF fibers to obtain a predictive model of SAF performance for aiding in design, development and operation of the SAF. 3. Design and fabricate SAF modules capable of reducing normal anti-A levels from whole body blood volumes down to the accepted clinical target for ABO-incompatible transplantation. Perform in-vitro evaluation of Ab capture from these "clinical" SAFs. Perform acute calf experiments to assess anti-A capture in-vivo and the overall in-vivo biocompatibility of the "clinical" SAF prototypes. While anti-A removal is the subject of this grant, the proposed work will provide a scientific framework for the design and operation of effective SAF devices targeting other pathogenic Abs including anti-B blood group Abs, a less clinically significant but still important impediment to ABO-incompatible transplantation.