(657a) Porous Membranes With Tailored Protein Selectivity By Grafting Or Pore-Filling With Multifunctional Polymers

Porous membranes with tailored protein selectivity by grafting or pore-filling with multifunctional polymers

Mathias Ulbricht, Nadia Adrus, Sebastian Schwark, Qian Yang, Dongxu Yin

Lehrstuhl für Technische Chemie II, Universität Duisburg-Essen, 45117 Essen, Germany, mathias.ulbricht@uni-essen.de

There is strong interest in using the highly selective recognition phenomena known from biological systems for technical applications. Synthetic membranes are an attractive platform because they can be used in various formats and configurations, as separator or contactor, to facilitate separation processes [1]. Here we focus on porous membranes with tailored biomimetic polymeric hydrogel layers with their primary use in protein separation [2]. However such membranes could also be interesting as combined recognition/transducer element in sensor systems [2].

Separations using macroporous membrane adsorbers combine fast convective transport through pores with selective and reversible binding of the target substances on functionalized pore walls. This is one example for the use of membranes as contactor. There is large interest in improving the performance for established materials and developing novel materials. We will discuss recent own work toward higher affinity and selectivity for specific proteins based on grafting of functional polymeric layers to various porous polymeric membranes. A high binding capacity is obtained by well-defined three-dimensional layer architectures; using controlled surface-initiated polymerization methods is crucial to achieve that goal. Examples include synthetic glycopolymers [3], zwitterionic polymers [4] and polymers presenting mixtures of different binding groups for epitops on protein surfaces [5]. In all these cases, cooperative multivalent binding is a key to achieve high selectivity. As an alternative we present the preparation of protein-imprinted polymeric layers obtained by a novel two-step grafting method where protein is used as template to create specific binding sites in a cross-linked functional hydrogel layer [6]. The transfer of preparations from model isoporous track-etched membranes to commercial polymeric base membranes with higher capacity, and the resulting protein binding selectivities and capacities under dynamic conditions will also be discussed.

Finally, the combination of reactive pore-filling with functional hydrogel via in situ cross-linking polymerization toward a tunable and switchable ultrafiltration membrane [7] with the preparation of protein-imprinted hydrogels [8] will be explored with the ultimate aim to obtain membranes where the barrier permeability is regulated by the presence of a specific protein.

[1]     E. Drioli, L. Giorno (Ed.), Membrane operations: Innovative separations and trans­formations, Wiley–VCH, Weinheim, 2009.

[2]     Q. Yang, N. Adrus, F. Tomicki, M. Ulbricht, J. Mater. Chem. 2011, 21, 2783.

[3]     Q. Yang, M. Ulbricht, Macromolecules 2011, 44, 1303-1310.

[4]     Q. Yang, M. Ulbricht, Chem. Mater. 2012, 24, 2943-2951.

[5]     S. Schwark, M. Ulbricht, Eur. Polym. J. 2012, 48, 1914-1922.

[6]     D. Yin, M. Ulbricht, J. Mater. Chem. B 2013, accepted.

[7]     N. Adrus, M. Ulbricht, J. Mater. Chem. 2012, 22, 3088-3098.

[8]     N. Adrus, M. Ulbricht, Polymer 2012, 53, 4359-4366.