Ultrafiltration and Virus Removal: A Mini Review of Recent Patents

In this paper, virus purification and removal by ultrafiltration are reviewed with specific focus on the patent literature. Membrane ultrafiltration is a pressure driven process which has a wide spectrum of industrial applications but is most attractive for sensitive biological streams carrying molecules like proteins. This process has thus naturally been adopted for the removal of viruses from blood and biopharmaceutical streams as well as for virus removal from drinking water. Safety regulations and associated penalties provide further incentives for limiting virus titers in such bioprocessing. Virus ultrafiltration aims at flux improvement, higher efficiency of removal and elongated filter life. In this regard, the proper choice of membrane material and technique is essential. Recent patents show strives in two directions namely inventions on membrane material design and filtration configuration and operation (methods). The diversity of biological fluids is seen to be a continuous challenge for researchers aiming for generic filtration methods for virus removal.