Oxygen Carrying Capacity of Totally Synthetic Oxygen Carrier-Lipidheme-Microsphere-

通过用合成脂血红素覆盖临床可用的脂肪滴（甘油三酯微球）来生产全合成携氧物质（人工红细胞）。因此，脂肪滴被用作脂质血红素作为氧载体的载体。这种人工红细胞替代物的尺寸为103 <plus-minus>29 nm。比重、粘度和渗透压与人体血液非常相似。体外研究其氧结合速度快、可逆，P50为40 mmHg。在血液中的半衰期为10-13小时。对比格犬进行了高达循环血量60%的交换输血，结果表明这种红血替代物向组织的氧输送量约为50 ml/min，相当于总氧输送量的40%。该氧载体的耗氧量为25 ml/min，相当于总耗氧量的约25%。在高达80%的交换输血中，由于严重的低白蛋白血症导致肺水肿，难以维持比格犬的生命。为了继续实验，必须使用全心肺转流。另一种设想是制造具有常压的人工氧载体。我们现在正在通过使用包埋脂素的白蛋白来生产这种材料。作为灌注液，白蛋白是强制性的，以增加对该脂质血红素微球的胶体粘附压力。白蛋白具有胶体吸附压，是脂质血红素的载体，是氧的载体。

Totally synthetic oxygen carrying substance (artificial red cell) was produced by covering clinically available fat droplets (triglyceride microsphers) with synthetic lipidhemes. Thus fat droplets were used as vehicles of lipidhemes as oxygen carrier. The size of this artificial red blood cell substitute is 103 <plus-minus> 29nm. Specific gravity, viscosity and osmotic pressure were very similar to that of human blood. In vitro study its oxygen binding was reversible and fast, the P50 was 40mmHg. Half life time in blood was 10-13 hourExchange transfusion in beagles upto 60% of circulating blood volume showed that oxygen transport to the tissue by this red blood substitute was about 50ml/min which corresponded about 40% of total oxygen transport. Oxygen consumption from this oxygen carrier was 25ml/min which corresponded about 25% of total oxygen consumption. In exchange transfusion upto 80%, it was difficult to keep beagles alive because of pulmonary edema due to severe hypoalbuminemia. To continue experiment it was necessaty to use total cardiopulmonary bypass. Another idea is to produce artificial oxygen carrier which has oncotic pressure. We are now producing this kind of material by using albumin in which lipidhemes are embedded. As perfusate albumin was mandatory to increase colloid oncotic pressure to this lipidheme microsphere. Albumin which has colloid oncotic pressure, is used as vehicles of lipid heme as oxygen carrier.