Biomimetic Approach to the Fabrication of Red Blood Cell Mimics

描述（由申请人提供）：尽管有大量投资，但在开发和制造血液替代品方面有许多失败的尝试，目前在北美或欧洲还没有批准用作血液替代品的产品。我们建议在这个应用程序中采取仿生方法的红细胞（RBC）的设计，使用一个强大的纳米成型技术，称为打印TM（粒子复制非润湿模板）在北卡罗来纳州大学在查佩尔山。PRINT TM将用于合成形状特异性、胶体稳定的水凝胶颗粒，其尺寸和机械性能类似于红细胞，并且可以通过脾脏中3微米大小的窦状隙的方式单独变形。用于设计合成血液的先前方法集中于i）可溶解大量血液气体的碳氟化合物乳液; ii）聚乙二醇化血红蛋白;和iii）血红蛋白的脂质体递送。因此，没有人报道直接模塑具有与RBC相同的进化设计形状和变形性或模量的RBC模拟物。 PRINT TM成型技术使我们能够独立设计和研究真正的血液替代品所需的关键标准，包括：形状控制、颗粒模量或灵活性、表面化学和表面配体（包括自身标记）、流动特性和气体传输特性。模制颗粒能够隔离血红蛋白和变构效应物作为货物，防止游离血红蛋白的释放和循环，以促进类似生命的携氧能力，但使其处于使其与各种器官物理接触隔离的形式，以避免与游离血红蛋白及其交联衍生物相关的记录的副作用。此外，我们还建议将“自身标记物”结合到这些可变形的模制RBC模拟物上，以最大限度地减少网状内皮系统（RES）的消除。该计划的主要目标将是开发一种氧载体，该氧载体具有长循环，并具有经典的S形氧平衡曲线，其表面积与体积比与真正的RBC相关，以获得体外和体内研究所证明的最佳氧携带和释放能力。 开发安全有效的合成血液替代品的必要性是显而易见的。据估计，到2030年，仅在美国就将短缺多达400万单位的献血者血液。此外，由当前血液供应传播疾病的风险增加，包括HIV、甲型肝炎病毒、B19细小病毒、丙型肝炎病毒和传染性朊病毒蛋白 与变异型克雅氏病、疯牛病和羊瘙痒病有关的病原体。血液供应的军事用途也很清楚。尤其是不需要血型匹配的货架稳定用品。除了血液供应之外，还非常需要创新的氧气输送方法来治疗诸如中风、心肌梗塞、冠状动脉阻塞、用于移植的器官保存和恶性疾病等病症，这些病症每年影响超过400万美国人。

DESCRIPTION (provided by applicant): Despite substantial investment, there are many failed attempts to develop and manufacture a blood substitute and at this time there are no currently approved products for use as blood substitutes in North America or Europe. We propose in this application to take a biomimetic approach to the design of red blood cells (RBC) using a powerful nano-molding technique called PRINT TM (Particle Replication in Non-wetting Templates) developed at the University of North Carolina at Chapel Hill. PRINT TM will be used synthesize shape-specific, colloidally stable, hydrogel particles with dimensions and mechanical properties which resemble red blood cells and that are individually deformable in a manner to allow them to pass through the 3 micron sized sinusoids in the spleen. Previous approaches for the design of synthetic blood have focused on i) fluorocarbon emulsions which can dissolve large amounts of blood gases; ii) PEGylated hemoglobin; and iii) liposomal delivery of hemoglobin. Heretofore, no one has reported direct molding of RBC mimics which have the same evolutionarily designed shapes and deformability or modulus as RBCs. The PRINT TM molding technique allows us to independently design and investigate the key criteria necessary for a true replacement for blood, including: shape control, particle modulus or flexibility, surface chemistry and surface ligands including markers of self, flow characteristics and gas transport characteristics. The molded particles are able to sequester hemoglobin and allosteric effectors as a cargo, preventing the release and circulation of free-hemoglobin, to facilitate life-like oxygen carrying capacity, but have it in a form that isolates it from physical contact with various organs to avoid the documented side effects associated with free hemoglobin and its cross-linked derivatives. In addition, we also propose to conjugate "markers of self" onto these deformable molded RBC mimics to minimize elimination by the reticuloendothelial system (RES). Key goals of the program will be to develop an oxygen carrier that is long circulating and has the classical sigmoidal shape of the oxygen equilibrium curve with a surface to volume ratio associated with a true RBC for optimal oxygen carrying and release capacity as demonstrated by in vitro and in vivo studies. The need to develop safe and effective synthetic blood substitutes is clear. There will be an estimated shortage of as much as 4 million units of donor blood in the United States alone by 2030. In addition, there is increasing risk of disease transmission from current blood supplies including HIV, Hepatitis A virus, B19 parvovirus, Hepatitis C virus, and infectious prion proteins the agents associated with variant Creutzfeldt-Jakob disease, mad cow disease, and scrapie. Military uses of blood supplies are also clear. Especially shelf-stable supplies that don't require blood antigen type matching. Beyond blood supply, there is a significant need for innovative oxygen delivery approaches to treat such conditions as stroke, myocardial infarction, coronary blockage, organ preservation for transplantation, and malignant disease which affect more than 4 million Americans each year.