Triple threat bismuth peptide imaging in cells.

Area of Science:

• Biomedical research
• Nanotechnology
• Pharmacology

Background:

• Bismuth peptides are a novel class of pharmaceutical agents.
• Cell-penetrating bismuth peptides' cellular interactions and stability are poorly understood.
• Visualization methods for intracellular bismuth peptides are needed.

Purpose of the Study:

• To synthesize and evaluate cell-penetrating bismuth peptides conjugated to fluorescent dyes.
• To investigate the cellular uptake and intracellular localization of these conjugates.
• To identify robust fluorescent tags for multimodal imaging of bismuth peptides.

Main Methods:

• Synthesis of bismuth peptides conjugated with naphthalimide, coumarin, and rhodamine B dyes and their brominated analogues.
• Cellular uptake studies in SKOV-3 cells.
• Multimodal imaging using X-ray fluorescence microscopy (XFM) for bismuth and bromine, and optical fluorescence microscopy.

Main Results:

• Co-localization of bromine, bismuth, and fluorescent dyes within the cytosol and cellular compartments.
• Confirmation that bismuth-peptide conjugates enter cells intact.
• Naphthalimide and its brominated derivative demonstrated superior robustness for multimodal imaging.

Conclusions:

• Cell-penetrating bismuth peptides can successfully enter SKOV-3 cells intact.
• Naphthalimide-based conjugates are suitable for multimodal imaging of bismuth peptides.
• This study provides a foundation for visualizing bismuth peptides in cellular environments.