Czermak P, Ebrahimi M, Catapano G
Institute of Biopharmaceutical Technology, University of Applied Sciences Giessen-Friedberg, Giessen, Germany.
Int J Artif Organs. 2005 Jul;28(7):694-700. doi: 10.1177/039139880502800708.
Poor water properties, use of concentrated bicarbonate, and biofilm growth in pipes and storage tanks often cause dialysis water and dialysate contamination with bacteria and endotoxins. High-flux dialysis with bicarbonate may favor endotoxin transfer from the dialysate into the blood exposing patients to serious short-and long-term side effects. Ultrafiltration across hydrophobic synthetic membranes effectively removes endotoxins from dialysis water by combined filtration and adsorption. However, repeated sterilization worsens the membrane separation properties,and limits their use. Ceramic membranes are generally more resistant to harsh operating conditions than polymeric membranes, and may represent an alternative for endotoxin removal. Previously, we proved that the ceramic membranes commercially available at that time were not retentive enough to ensure production of endotoxin-free dialysis water. In this paper, we investigated the endotoxin removal capacity of new generation commercial ceramic membranes with nominal molecular weight cut-off down to 1,000. In dead-end filtration, all investigated membranes produced water meeting, the European standards, or close to,when challenged with low endotoxin concentrations, but only one membrane type succeeded at high endotoxin concentrations. In cross-flow filtration, none produced water meeting the European standard. Moreover, sterilization and rinsing procedures altered the separation properties of two out of three membrane types.
水质不佳、使用浓缩碳酸氢盐以及管道和储水箱中生物膜的生长，常常导致透析用水和透析液被细菌和内毒素污染。使用碳酸氢盐进行高通量透析可能会促使内毒素从透析液转移到血液中，使患者面临严重的短期和长期副作用。通过疏水性合成膜进行超滤，可通过过滤和吸附相结合的方式有效去除透析水中的内毒素。然而，反复灭菌会使膜的分离性能变差，并限制其使用。陶瓷膜通常比聚合物膜更能耐受恶劣的操作条件，可能是去除内毒素的一种替代选择。此前，我们证明当时市售的陶瓷膜截留能力不足，无法确保生产无内毒素的透析用水。在本文中，我们研究了截留分子量低至1000的新一代商用陶瓷膜的内毒素去除能力。在死端过滤中，当受到低内毒素浓度挑战时，所有研究的膜产生的水均符合或接近欧洲标准，但在高内毒素浓度下，只有一种膜类型成功达标。在错流过滤中，没有一种膜产生的水符合欧洲标准。此外，灭菌和冲洗程序改变了三种膜类型中的两种的分离性能。
