Surface zwitterionization of polypropylene nonwoven fabric by dielectric barrier discharge plasma for efficient leukodepletion

This work reports the development of highly effective leukoreduction filters using dielectric barrier discharge (DBD) plasma applied to polypropylene (PP) nonwoven coated with zwitterionic sulfobetaine methacrylate (SBMA) monomer. The surface modification had no effect on the structural characteristics (pore size, porosity) of the material, but significantly affected its surface chemistry. Mapping IR showed that a homogeneous layer of polySBMA was grown on the surface, resulting in the formation of a superhydrophilic interface that could be immediately wetted by water (the water contact angle reached zero in 0.14 s). This enabled gravity-driven filtration of whole blood. The use of 1, 3, or 5 layers of the optimized grafted membrane obtained after 160 scans in the DBD reactor resulted in 78%, 96.1%, and 99.8% leukocytes removal, respectively, outperforming the commercial alternatives tested. At the same time, more than 90% of erythrocytes were recovered. The large pore size and the wetting behavior of the membrane allow the passage of small cells while limiting cell interactions with the membrane material as the modification reduced leukocyte adhesion by approximately 91%. After 3 washings with PBS, 43% of the attached leukocytes could be detached from the grafted membrane, which is significantly higher than the recovery measured with commercial membranes. Therefore, the membranes are not only efficient as leukoreduction filters, but could also be a viable solution for cell recovery.

Automated summary

This study developed highly effective leukoreduction filters by using dielectric barrier discharge (DBD) plasma on polypropylene (PP) nonwoven coated with zwitterionic sulfobetaine methacrylate (SBMA) monomer. The modified surface did not affect the material's structural characteristics, but greatly changed its surface chemistry. The optimized grafted membrane showed excellent performance in removing leukocytes, outperforming commercial alternatives while maintaining high erythrocyte recovery.