Cancer Cell Targeting Via Selective Transferrin Receptor Labeling Using Protein-Derived Carbon Dots.

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Materials Science

Background:

• Carbon dots (CDs) are promising fluorescent probes for bioimaging and biosensing.
• A key limitation of CDs is their lack of specific affinity for biomolecules, hindering targeted applications.
• Nanoparticles with intrinsic target affinity are valuable for imaging, cytometry, and therapeutics.

Purpose of the Study:

• To synthesize, for the first time, carbon dots (CDs) with inherent affinity for the transferrin receptor (CD71).
• To demonstrate that precursor protein selection can directly tune nanoparticle targeting capabilities.
• To validate the retention of protein-derived functional properties on the nanoparticle surface.

Main Methods:

• Synthesis of transferrin (Tf)-derived CDs by incorporating transferrin into the precursor selection.
• Fourier transform infrared (FTIR) spectroscopy to confirm the retention of protein peptides on the CD surface.
• Cell-based assays using the HL60 human leukemia cell line to assess CD71 targeting and cellular uptake mechanisms.

Main Results:

• Successfully synthesized Tf-derived CDs with violet fluorescence and 7.9% quantum yield.
• FTIR and cell assays confirmed the selective binding of Tf-CDs to CD71, a cancer biomarker.
• Demonstrated specific triggering of transferrin-mediated endocytosis via clathrin-coated pits in HL60 cells.

Conclusions:

• This novel method allows for the direct tuning of nanoparticle affinity through precursor protein selection.
• Tf-derived CDs exhibit selective targeting of CD71, a receptor overexpressed in various cancers.
• This approach offers a versatile platform for developing targeted nanoparticles for biosensing, bioimaging, and therapeutics by utilizing other disease biomarkers.