(616h) Antifouling Surfaces Inspired By Nature: Nuclear Pore Complex

Membrane fouling, the process in which proteins adhere to the external and internal surface of synthetic membranes, is considered a major limitation in membrane filtration of biofluids. This causes permeation flux and changes in selectivity, with the overall effect of reducing membrane performance and increasing process cost. In the past 30 years researchers have focused on how to reduce membrane fouling. The Whitesides group has published a set of criteria for obtaining protein-resistant chemistries, viz. the surface of such membranes or materials should (i) be hydrophilic, (ii) include hydrogen bond acceptors, (iii) do not include hydrogen bond donors, and (iv) be net electrically neutral. An alternative approach to producing synthetic surfaces based on these criteria is to observe Nature’s method of producing protein-resistant surfaces. In particular, we focused on the Nuclear Pore Complex (NPC), the sole mediator of exchange between the nucleus and the cytoplasm in all eukaryotic cells. Protein transport across the NPC is fast, energy-dependent (to give directionality), often receptor-mediated and most important it occurs in the absence of unwanted fouling. For this reason we focused on “NPC-proteins” and covalently attached them on a sensor surface to test their antifouling properties. A series of different proteins, including BSA, were used to test the efficacy of this new biomimetic surface. For comparison (control), we also tested surfaces modified with other inert proteins and PEG, the gold standard with respect to protein-resistance. A quartz crystal microbalance with dissipation was used in all these experiments.