Heparin is an anticoagulant sourced from animal tissues. In the 1990s, bovine-sourced heparin was withdrawn from the U.S. market due to a theoretical concern that the bovine spongiform encephalopathy (BSE) agent might contaminate crude heparin and spread to humans as variant Creutzfeldt-Jakob disease. Only porcine intestinal heparin is now marketed in the U.S. FDA has encouraged the reintroduction of bovine heparin. We applied a scaled-down laboratory model process to produce heparin as an active pharmaceutical ingredient (API) starting from bovine intestinal mucosa. The process consisted of two phases. To model the first phase, we applied enzymatic proteolysis, anionic resin separation and methanol precipitation of crude heparin. Bovine intestinal mucosa was spiked with BSE or scrapie agents. We assayed BSE- or scrapie-associated prion protein (PrP^TSE) using the Real-Time Quaking-Induced Conversion (RT-QuIC) assay at each step. The process reduced PrP^TSE by 4 log₁₀ and 6 log₁₀ from BSE-spiked and scrapie-spiked mucosa, respectively. To model the entire process, we spiked mucosa with scrapie agent and produced heparin API, reducing PrP^TSE by 6.7 log₁₀. The purification processes removed large amounts of PrP^TSE from the final products. Heparin purification together with careful sourcing of raw materials should allow safely reintroducing bovine heparin in the U.S.

肝素是一种来源于动物组织的抗凝剂。在 1990 年代，牛源性肝素从美国市场撤出，原因是理论上担心牛海绵状脑病 (BSE) 制剂可能会污染粗肝素并作为变异克雅氏病传播给人类。现在只有猪肠肝素在美国上市，FDA 鼓励重新引入牛肝素。我们采用缩小的实验室模型工艺从牛肠粘膜开始生产作为活性药物成分 (API) 的肝素。该过程包括两个阶段。为了模拟第一阶段，我们应用了酶促蛋白水解、阴离子树脂分离和粗肝素的甲醇沉淀。牛肠黏膜掺入 BSE 或痒病剂。^TSE ) 在每个步骤中使用实时振动诱导转换 (RT-QuIC) 分析。该过程使来自 BSE 尖刺和痒病尖刺粘膜的PrP ^{TSE 分别}减少了 4 log ₁₀和 6 log ₁₀。为了模拟整个过程，我们在粘膜中加入瘙痒病剂并生产肝素 API，将 PrP ^TSE降低6.7 log ₁₀。纯化过程从最终产品中去除了大量的 PrP ^TSE。肝素纯化与原材料的谨慎采购应允许在美国安全地重新引入牛肝素