Design of Extracorporeal Specific Antibody Filters

描述(由申请人提供)： 这项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)。受体抗-A抗体是ABO血型不合移植最显著的临床障碍。SAFS将由中空纤维膜组成，其中A抗原(AGS)附着在纤维腔表面。在SAF的全血灌流过程中，靶向抗体与AGS结合，并被移除。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能够从循环血液中捕获临床上有用的抗-A水平的SAF。本研究的具体目的是：1.合成三糖及其相关的四糖A抗原。利用这些，我们将固定化几种合成的银偶联物来测试膜，并评估它们与Ag类型和组成有关的抗体结合作用和功能能力，包括间隔物分子的使用。我们将用最有希望的合成银结合物来制造迷你SAF模块，我们将验证它们的抗体结合特性，并在台式灌流实验中评估初步的血液生物相容性。2.利用台式灌流回路评价SAF组件中单抗捕获的传质特性。我们将研究抗体清除率与关键操作参数的关系，包括纤维上的Ag类型和负载量、管腔流速、入口抗体浓度、超滤率以及红细胞的影响。我们将对SAF纤维中单抗传输的实验间隙和理论模拟进行比较，以获得SAF性能的预测模型，为SAF的设计、开发和操作提供帮助。3.设计和制造SAF模块，能够将正常的抗-A水平从全身血液容量降低到ABO血型不合移植的可接受临床靶点。对这些“临床”SAF中的抗体捕获进行体外评估。进行小牛急性实验，以评估体内抗A抗体捕获和临床SAF原型的整体体内生物相容性。虽然去除抗-A抗体是这项拨款的主题，但拟议的工作将为设计和操作针对其他致病抗体的有效SAF设备提供科学框架，包括抗-B血型抗体，这是ABO血型不合移植的一个临床意义较小但仍然重要的障碍。

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.