Generating Aptamers Interacting with Polymeric Surfaces for Biofunctionalization.

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Molecular Biology

Background:

• Biofunctionalization of surfaces is crucial for cell recruitment and biomaterial applications.
• Traditional methods often rely on covalent binding, but noncovalent strategies offer an alternative.
• Multivalent noncovalent interactions can immobilize biomacromolecules onto surfaces.

Purpose of the Study:

• To screen for polymer-binding DNA aptamers using an in vitro selection process.
• To achieve area-wide surface functionalization via noncovalent aptamer-polymer interactions.
• To investigate the binding mechanisms and stability of aptamers interacting with different polymers.

Main Methods:

• Utilized a DNA-based in vitro selection (SELEX) method to enrich aptamers.
• Screened aptamers against candidate biomaterials: poly(ether imide) (PEI), polystyrene, and poly[ethylene-co-(vinyl acetate)].
• Analyzed aptamer binding motifs and stability based on polymer interaction valences.

Main Results:

• Successfully enriched multivalent aptamers capable of area-wide surface functionalization.
• Identified thymine-dominated aptamer binding motifs, indicating preferential interaction with thymine.
• Attributed preferential thymine interaction to favorable chemical structure, reduced electrostatic repulsion, and hydrophobic effects.
• Demonstrated that aptamer binding stability correlates with available valences, leading to more stable PEI functionalization.

Conclusions:

• DNA aptamers can be effectively selected for noncovalent binding to polymers.
• This method provides a stable approach for biofunctionalizing surfaces with biomacromolecules.
• The findings offer a new strategy for designing advanced biomaterials with tailored surface properties.