Visualising nanoscale restructuring of a cellular membrane triggered by polyelectrolyte microcapsules.

Area of Science:

• Biomaterials Science
• Cell Biology
• Nanotechnology

Background:

• Polymer-based multilayer microencapsulation is a key strategy for intracellular drug delivery.
• The precise mechanisms of microcapsule internalization by cell membranes remain poorly understood.
• Real-time, nanoscale observation of these interactions is crucial for optimizing drug delivery systems.

Purpose of the Study:

• To investigate the nanoscale processes of polymer microcapsule internalization into A549 cells.
• To visualize the dynamic interactions between cellular membranes and microcapsules in real time.
• To elucidate the role of membrane mechanics during microcapsule uptake.

Main Methods:

• Utilized Scanning Ion Conductance Microscopy (SICM) for high-resolution, real-time imaging.
• Simultaneously captured topographical and local elastic modulus data during microcapsule internalization.
• Observed microcapsule uptake in A549 cell cultures without disrupting the process.

Main Results:

• Microcapsules induced membrane protrusions, a necessary but insufficient step for internalization.
• Nanoscale restructuring of protrusions into smooth layers covering the microcapsules was observed.
• Elastic modulus mapping revealed structural changes during membrane extension and subsequent capsule buckling.

Conclusions:

• SICM provides unprecedented nanoscale insights into cellular membrane-microcapsule interactions.
• The study details the dynamic membrane remodeling required for successful microcapsule internalization.
• This methodology offers a powerful tool for understanding nanostructured material-cell interfaces.