Generating Aptamers Interacting with Polymeric Surfaces for Biofunctionalization.
Common strategies for biofunctionalization of surfaces comprise the immobilization of bioactive molecules used as cell-binding ligands for cell recruitment. Besides covalent binding, multivalent noncovalent physical forces between substrate and ligand are an alternative way to equip surfaces with biomacromolecules. In this study, polymer binding ligands are screened by means of a DNA-based in vitro selection process. As candidate biomaterials poly(ether imide) (PEI), polystyrene, and poly[ethylene-co-(vinyl acetate)] are selected, due to their different chemical structure, but similar macroscopic interface properties, allowing physical interaction with nucleotide bases by varying valences. Multivalent interacting aptamers are successfully enriched by SELEX method and an area-wide surface functionalization is achieved, which can be used for further binding of bioactive molecules. In vitro selection against the polymers result in thymine-dominated aptamer binding motifs. The preferential interaction with thymine is attributed to its chemical structure, connected with a decreased electrostatic repulsion of the π-system and the hydrophobic character maximizing entropy. The aptamer binding stability correlates with available valences for interaction, resulting in a more stable functionalization of PEI.
Institute of Biomaterial Science and Berlin-Brandenburger Centre for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Kantstraße 55, 14513, Teltow, Germany.
Christian
C
Schulz
Charité - Universitätsmedizin Berlin, Berlin-Brandenburger Centre for Regenerative Therapies, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353, Berlin, Germany.
Jochen
J
Hecht
Institute of Biomaterial Science and Berlin-Brandenburger Centre for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Kantstraße 55, 14513, Teltow, Germany.
Anne
A
Krüger-Genge
Institute of Biomaterial Science and Berlin-Brandenburger Centre for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Kantstraße 55, 14513, Teltow, Germany.|Helmholtz Virtual Institute, Multifunctional Biomaterials for Medicine, Kantstraße 55, 14513, Teltow, Germany.
Karl
K
Kratz
Institute of Biomaterial Science and Berlin-Brandenburger Centre for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Kantstraße 55, 14513, Teltow, Germany.|Helmholtz Virtual Institute, Multifunctional Biomaterials for Medicine, Kantstraße 55, 14513, Teltow, Germany.
Friedrich
F
Jung
Institute of Biomaterial Science and Berlin-Brandenburger Centre for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Kantstraße 55, 14513, Teltow, Germany.|Helmholtz Virtual Institute, Multifunctional Biomaterials for Medicine, Kantstraße 55, 14513, Teltow, Germany.
Andreas
A
Lendlein
D052157:Aptamers, Nucleotide / Q000737:chemistry* / Q000378:metabolism*; D011108:Polymers / Q000737:chemistry* / Q000378:metabolism*; D052156:SELEX Aptamer Technique / Q000379:methods*; D013499:Surface Properties
D052157:Aptamers, Nucleotide; D011108:Polymers
DNA-aptamers; SELEX; physical functionalization; polymers; surface interactions