Smart Biomedical Membranes for Blood Separation
This chapter presents current efforts to design smart materials for blood separation, which do not rely on molecular sieving only, but on mechanisms of interactions between the membrane and the blood component to isolate. Although concepts have been introduced, there is more to do than has ever been done on this topic. This chapter stresses the need for a specific combination of materials to separate the component of interest from the bloodstream without inducing blood coagulation. PEGylated, zwitterionic and pseudo-zwitterionic materials can all improve the hemocompatibility of the membrane design. But to perform a smart separation, a charge bias has to be introduced by incorporating charged polymers, or a stimuli-responsive polymer has to be grafted which interactions with the blood component are tuned by environmental conditions. Attention is also given to methods for preparing supporting layers, poly(vinylidene fluoride)-based or polypropylene-based. Finally, examples of reported smart blood separations are scrutinized, including the separation of proteins from whole blood, the development of leukocyte depletion or platelet concentration filters. We end this chapter with an identification of the current challenges to overcome to expand the development of smart membranes for blood separation.