Intermolecular forces such as hydrogen bonding and electrostatics critically influence biomolecule–membrane interactions in membrane-based separations. Contrary to the common view that hydrophilic surfaces resist protein adhesion alone, we show that hydrogen bonding can promote adhesion when interfacial water is displaced
1. A modified polyethersulfone (mPES) membrane exhibited threefold stronger adhesion to streptavidin (hydrophilic protein) than a less hydrogen-bonding modified polyvinylidene fluoride (mPVDF) membrane, as quantified by atomic force microscopy and supported by surface energy and solvation shell spectroscopy. Extending this principle, we demonstrate a scalable, ligand-free method to purify single-stranded mRNA (ss-mRNA) from immunogenic double-stranded RNA (dsRNA) using a positively charged synthetic membrane
2. High recovery (~ 100 %) and separation efficiency were achieved at alkaline pH and rapid flow rates (1.5 mL/min). The addition of the polyamine spermine selectively neutralized dsRNA, thereby enhancing selectivity. Together, these studies highlight the key role of hydrogen bonding and electrostatic interactions in designing membranes for efficient protein and nucleic acid separations.
References
(1) Karla, S.; Sorci, S.; Moussa, M.; Banik, R.; Petersen, P. B.; Plawsky, J.; Belfort, G. Hydrogen bonding controls protein-polymer membrane adhesion. J. Colloid and Interface Science 2026, 701, 138530. DOI: https://doi.org/10.1016/j.jcis.2025.138530.
(2) Neuman, T. G.; Banik, R.; Karla, S.; Hu, M.; Hartin, A.; Karande, P.; Kilduff, J.; Belfort, G. Tuning hydrogen bonds and electrostatics with convection for purifying mRNA: A paradigm shift. Scientific Reports 2025, 11 eadv8656. DOI: 10.1126/sciadv.adv8656.
