An engineered coiled-coil polypeptide assembled onto quantum dots for targeted cell imaging.

Area of Science:

• Bioconjugation Chemistry
• Nanomaterials Science
• Cellular Imaging

Background:

• Quantum dots (QDs) are semiconductor nanocrystals with unique optical properties.
• Developing targeted and efficient probes for cellular imaging remains a challenge.
• Existing QD probes often face limitations in luminescence, cellular uptake, and cytotoxicity.

Purpose of the Study:

• To develop novel QD-polypeptide probes utilizing metal-affinity interactions.
• To investigate the impact of polypeptide charge on QD properties and cellular uptake.
• To evaluate the potential of these probes for targeted cell imaging.

Main Methods:

• Synthesized CdSe/ZnS core-shell QDs functionalized with polyhistidine-tagged polypeptides.
• Characterized QD-polypeptide probes for luminescence, size, and charge.
• Assessed nonspecific and targeted cellular uptake in HeLa cells.
• Evaluated in vitro cytotoxicity of QD-polypeptide probes.

Main Results:

• QD-polypeptide probes exhibited a 2-3 fold increase in luminescence compared to QD-GSH.
• Polypeptide charge significantly influenced nonspecific cellular uptake (negative < QD-GSH < positive).
• Targeted QD-ARGD probes enhanced uptake in αvβ3 overexpressing cells.
• QD-polypeptide probes demonstrated lower in vitro cytotoxicity than original QDs.

Conclusions:

• QD-polypeptide probes offer improved luminescence and tunable cellular interactions.
• These probes show potential for specific targeting and reduced cellular toxicity.
• The developed probes are promising for advanced applications in targeted cell imaging.