Hyaluronan-Conjugated Carbon Quantum Dots for Bioimaging Use.

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Oncology

Background:

• Targeted drug delivery and bioimaging face challenges with specificity.
• Hyaluronic acid (HA) is a natural ligand for CD44 receptors, often overexpressed on cancer cells.
• Nitrogen-doped carbon quantum dots (nCQDs) offer fluorescent properties but lack inherent targeting capabilities.

Purpose of the Study:

• To develop and evaluate hyaluronan-conjugated nitrogen-doped carbon quantum dots (HA-nCQDs) for targeted tumor bioimaging.
• To assess the potential of HA-nCQDs as carriers for targeted drug delivery into CD44-rich cancer cells.

Main Methods:

• Synthesis of HA-nCQD conjugates via carbodiimide coupling.
• Characterization of HA-nCQD fluorescence and quantum efficiency.
• Confocal microscopy to evaluate cellular internalization.
• In vivo studies using patient-derived breast cancer xenografts in mice to assess tumor specificity.

Main Results:

• HA-nCQDs retained fluorescence, with a 30% reduction in quantum efficiency compared to nCQDs.
• Enhanced internalization of HA-nCQDs by cancer cells was observed, mediated by CD44 receptor binding.
• High tumor specificity was achieved with both local and systemic injection of HA-nCQDs, demonstrated by a strong signal-to-noise ratio in vivo.
• Successful bioimaging of CD44-specific tumors in preclinical models.

Conclusions:

• HA-nCQDs are effective for bioimaging CD44-specific tumors in preclinical cancer models.
• The HA-nCQD conjugate demonstrates potential as a targeted delivery system for CD44-rich cancer cells.
• This approach offers a promising strategy for enhancing cancer diagnostics and therapeutics.