Exercising spatiotemporal control of cell attachment with optically transparent microelectrodes.

Area of Science:

• Biomaterials Engineering
• Surface Chemistry
• Cell Biology

Background:

• Controlling cell-surface interactions is crucial for tissue engineering and cell-based assays.
• Existing methods for biointerfacial control often lack spatial and temporal precision.

Purpose of the Study:

• To present a novel electrochemical approach for dynamically controlling biointerfacial properties of microelectrodes.
• To demonstrate the ability to switch surfaces between protein-resistant and protein-adhesive states.

Main Methods:

• Fabrication of indium tin oxide (ITO) microelectrodes on glass substrates.
• Modification of surfaces with poly(ethylene glycol) (PEG) silane to create nonfouling properties.
• Electrochemical monitoring using cyclic voltammetry with potassium ferricyanide.
• Electrical stimulation to induce PEG silane desorption.
• Surface characterization using Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS).

Main Results:

• PEG silane modification rendered ITO surfaces non-adhesive to proteins and cells.
• Application of a reductive potential (-1.4 V) caused PEG silane desorption, restoring adhesion.
• Electrical stimulation allowed selective switching of individual electrodes between nonfouling and adhesive states.
• Successful micropatterning of proteins and cells was achieved using this method.

Conclusions:

• Electrochemical control of biointerfacial properties offers precise spatial and temporal manipulation of cell adhesion.
• This technique enables the creation of complex micropatterned co-cultures.
• The approach holds potential for developing advanced in vitro models of native tissue complexity.