High-Resolution Imaging of Dendrimers Used in Drug Delivery via Scanning Probe Microscopy

Figure 3

Visualization of indomethacin features from high-resolution STM images. (a) A 40 × 40 nm² STM topographic image of G4 PAMAM-OH-(Pt²⁺)_𝑛-(Indo)_𝑚 dendrimers immobilized on Au(111). The inset in (a) is a 5 × 5 nm² high-resolution image of a single drug-loaded dendrimer from the same surface showing indomethacin features (red arrows) and a dendrimer intramolecular feature (blue arrow). (b) A 40 × 40 nm² STM topographic image of G4 PAMAM-OH-(Pt²⁺)_𝑛 dendrimers immobilized on Au(111). The 6 × 6 nm² inset is a bare dendrimer, where only intramolecular features are visible (blue arrows). All STM images were acquired at 0.3 V and 20 pA. The color scale is normalized to reflect the apparent height range of 0.00–0.85 nm.

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