Chemically tunable electrochemical dissolution of noncontinuous polyelectrolyte assemblies: an in situ study using...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Polyelectrolyte multilayers (PEMs) are versatile materials with tunable properties.
• Understanding their dissolution behavior is crucial for applications like drug delivery.
• Electrochemical methods offer precise control over material degradation.

Purpose of the Study:

• To investigate the electrochemically triggered dissolution of polyelectrolyte assemblies.
• To explore the influence of chemical cross-linking on dissolution kinetics and morphology.
• To assess the potential for controlled release applications.

Main Methods:

• In situ monitoring using electrochemical atomic force microscopy (ecAFM).
• Layer-by-layer deposition of poly-l-lysine (PLL) and hyaluronic acid (HA) on ITO electrodes.
• Varying experimental conditions and cross-linking densities.

Main Results:

• Distinct nanomorphologies of PEMs were observed and tracked during dissolution.
• Faster dissolution of coalesced structures compared to droplet-like assemblies.
• Slower and partial dissolution of covalently cross-linked PLL/HA assemblies, dependent on cross-link density.
• Readsorption of dissolved polyelectrolytes onto neighboring structures was observed.

Conclusions:

• Electrochemical dissolution of PEMs can be precisely tuned by chemical cross-linking.
• Cross-linking significantly reduces dissolution rates and extent.
• This controlled degradation opens avenues for advanced drug and gene delivery platforms with tailored release profiles.