McGowan Institute for Regenerative Medicine, University of Pittsburgh, 3025 East Carson Street, Pittsburgh, PA, 15203, USA.
J Mater Sci Mater Med. 2013 Nov;24(11):2611-21. doi: 10.1007/s10856-013-5006-2. Epub 2013 Jul 26.
Extracorporeal CO2 removal from circulating blood is a promising therapeutic modality for the treatment of acute respiratory failure. The enzyme carbonic anhydrase accelerates CO2 removal within gas exchange devices by locally catalyzing HCO3 (-) into gaseous CO2 within the blood. In this work, we covalently immobilized carbonic anhydrase on the surface of polypropylene hollow fiber membranes using glutaraldehyde activated chitosan tethering to amplify the density of reactive amine functional groups for enzyme immobilization. XPS and a colorimetric amine assay confirmed higher amine densities on the chitosan coated fiber compared to control fiber. Chitosan/CA coated fibers exhibited accelerated CO2 removal in scaled-down gas exchange devices in buffer and blood (115% enhancement vs. control, 37% enhancement vs. control, respectively). Carbonic anhydrase immobilized directly on hollow fiber membranes without chitosan tethering resulted in no enhancement in CO2 removal. Additionally, fibers coated with chitosan/carbonic anhydrase demonstrated reduced platelet adhesion when exposed to blood compared to control and heparin coated fibers.
从循环血液中体外去除二氧化碳是治疗急性呼吸衰竭的一种很有前途的治疗方法。酶碳酸酐酶通过在气体交换装置内局部催化血液中的 HCO3(-) 转化为气态 CO2 ，从而加速 CO2 的去除。在这项工作中，我们使用戊二醛激活壳聚糖将碳酸酐酶共价固定在聚丙烯中空纤维膜的表面上，以增加用于酶固定的反应性胺官能团的密度。XPS 和比色胺分析证实，与对照纤维相比，壳聚糖涂覆的纤维上具有更高的胺密度。壳聚糖/CA 涂覆的纤维在缓冲液和血液中的小型气体交换装置中表现出加速的 CO2 去除（与对照相比增强 115%，与对照相比增强 37%）。没有壳聚糖连接的碳酸酐酶直接固定在中空纤维膜上，不会增强 CO2 的去除。此外，与对照纤维和肝素涂层纤维相比，暴露于血液时，涂有壳聚糖/碳酸酐酶的纤维的血小板黏附减少。
