Aptamer based electrostatic-stimuli responsive surfaces for on-demand binding/unbinding of a specific ligand

Area of Science:

• Biomaterials Science
• Nanotechnology
• Biophysics

Background:

• Aptamers are nucleic acid or peptide molecules that bind to a specific target molecule.
• Stimuli-responsive materials can change their properties in response to external triggers.
• Controlled release of biomolecules is crucial for various applications, including diagnostics and therapeutics.

Purpose of the Study:

• To engineer an aptamer-functionalized surface for controllable binding and release of thrombin using electrical stimuli.
• To investigate the mechanism of electrical field-induced release of thrombin from aptamer-coated surfaces.
• To demonstrate the potential of this system for on-demand biomolecule manipulation.

Main Methods:

• Fabrication of aptamer-functionalized surfaces.
• Atomic force microscopy (AFM) to measure binding and height changes.
• Application of varying electrostatic fields to induce ligand release.
• Molecular dynamics (MD) simulations to analyze molecular interactions under electric fields.

Main Results:

• Specific binding of thrombin to anti-thrombin aptamer surfaces was confirmed by AFM.
• Positive electrical potential induced the release of thrombin from the surface.
• Negative electrical potential at higher magnitudes also led to molecule removal.
• MD simulations supported thrombin dissociation from aptamers under a positive electric field.

Conclusions:

• Aptamer-functionalized surfaces can achieve specific binding and electrically controlled release of target ligands like thrombin.
• Electrostatic fields offer a viable method for on-demand manipulation of biomolecule interactions on surfaces.
• This technology holds promise for applications requiring precise control over biomolecular binding and release.