Synthesis and characterization of a novel DTPA polymerized hemoglobin based oxygen carrier.
Synthesis and characterization of a novel DTPA polymerized hemoglobin based oxygen carrier.
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DOI：
10.1016/j.bbagen.2005.07.002
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发表时间：
2005-10
期刊：
影响因子：
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通讯作者：
C. Haney;P. Buehler;A. Gulati
中科院分区：
文献类型：
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作者：
C. Haney;P. Buehler;A. Gulati
目的本研究的目的是制备一种新型聚合血红蛋白（Hb）基氧载体（HBOC），旨在最大限度地减少 Hb 引起的高血压，同时采用简单且廉价的制备方法。使用环二乙烯三胺五乙酸（DTPA）聚合基质游离血红蛋白（SF-Hb）。方法从红细胞中分离SF-Hb，并在恒定浓度、pH 和持续时间下与 DTPA 反应。使用超滤去除低摩尔质量分数（<100 kDa）。通过分析摩尔质量、胶体渗透压和氧亲和力，确定反应和随后的超滤步骤是可重复的。最后，使用大鼠 50% 换血 (ET) 模型来评估 DTPA 聚合 SF-Hb (Poly-DTPA-Hb) 的血压反应。 结果Poly-DTPA-Hb 的数均摩尔质量为 128.7 kDa，加权平均值为 223.0 kDa。氧结合平衡表明氧亲和力较高（P50=5.1±0.01 mm Hg），而协同性较小（n=1.4）。 Poly-DTPA-Hb 和对照 DTPA 聚合人血清白蛋白 (Poly-DTPA-HSA) 在 ET 期间意外地引起大鼠急性低血压（平均动脉压比基线低约 45%）。 ET 期间发生的低血压被确定是由钙与 DTPA 相关蛋白结合介导的。在聚 DTPA 蛋白质制剂中添加氯化钙 (CaCl2) 可以减弱这种效应。 结论 环状 DTPA 酸酐可用于产生交联和聚合的血红蛋白，过程简单且成本低廉。然而，似乎需要在制剂中添加 CaCl2 以防止输注过程中钙螯合和随后的低血压。
OBJECTIVEThe purpose of this study was to prepare a novel polymerized hemoglobin (Hb) based oxygen carrier (HBOC) designed to minimize Hb induced hypertension, while employing a simple and inexpensive method of preparation. Cyclic-diethylenetriaminepentaacetic acid (DTPA) was used to polymerize stroma free Hb (SF-Hb).METHODSSF-Hb was isolated from red blood cells and reacted with DTPA at a constant concentration, pH, and duration. Low molar mass fractions (<100 kDa) were removed using ultrafiltration. Reactions and subsequent ultrafiltration steps were determined to be reproducible by analyzing molar mass, colloid osmotic pressure and oxygen affinity. Finally, a model of 50% exchange transfusion (ET) in rats was used to evaluate the blood pressure response to DTPA polymerized SF-Hb (Poly-DTPA-Hb).RESULTSPoly-DTPA-Hb demonstrated a number averaged molar mass of 128.7 kDa and a weighted average of 223.0 kDa. Oxygen binding equilibrium indicated high oxygen affinity (P50=5.1±0.01 mm Hg) and little cooperativity (n=1.4). Poly-DTPA-Hb and a control DTPA polymerized human serum albumin (Poly-DTPA-HSA) unexpectedly caused acute hypotension during the period of ET in rats (mean arterial pressure ≈45% less than baseline). Hypotension occurring over the period of ET was determined to be mediated by calcium binding to protein associated DTPA. This effect was attenuated by the addition of calcium chloride (CaCl2) to the Poly-DTPA protein preparations.CONCLUSIONSCyclic DTPA anhydride can be used to create cross-linked and polymerized hemoglobin, using a simple and inexpensive process. However, the addition of CaCl2to the preparation appears to be required to prevent calcium chelation and subsequent hypotension during infusion.