Efficient leukocyte removal and enhanced biocompatibility using PVDF membranes prepared by vapor-induced phase separation

To develop an efficient filter for removing white blood cells from whole blood, hydrophilic large-pore blended membranes of poly(vinylidene fluoride) (PVDF), polyvinyl pyrrolidone and polyethylene glycol, with good biocompatibility, were prepared using the process of vapor-induced phase separation at various PVDF concentrations. The results demonstrated that at a PVDF mass concentration of 14%, the membrane had increased surface roughness, significantly enhanced hydrophilicity and wettability, and a wetting time of 8 s. The surface roughness of the membrane was also reduced to 31.637 nm. Furthermore, hemolysis rate and protein adsorption tests indicated that the blended membranes possessed excellent biocompatibility. They were reduced to 2.48% and 34.44 μg·cm –2 , respectively. The pore size of the fabricated membrane was relatively large, which reached approximately 8 μm respectively, satisfying the filtration requirements. Lastly, the effects of different temperatures and multi-layered filters on leukocyte removal and the retention of red blood cells and platelets from whole blood were evaluated. The results revealed that the leukocyte removal rate was highest at 4 °C and with three membrane layers, the leukocyte removal rate was highest, reaching 98.36%, while the RBC and platelet content remained nearly unchanged compared with the original blood. This study provides a new approach for blood cell separation that is expected to play a significant role in medical fields such as blood transfusion demonstrating great potential for application and innovation.