One-Step Colloidal Synthesis of Non-Toxic Electroactive Carbon Dots with a Better Threshold Cytotoxicity and...

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Materials Science

Background:

• Carbon dots (CDs) are <10 nm fluorescent nanomaterials with potential biomedical applications.
• CD toxicity and cytocompatibility are critical concerns influenced by synthesis and morphology.
• Understanding these factors is crucial for safe and effective use in biological systems.

Purpose of the Study:

• To develop a one-step synthesis for various carbon dots (CDs).
• To evaluate the cytocompatibility and cellular uptake of different CDs in human mesenchymal stem cells (hMSCs).
• To identify CDs with optimal properties for biomedical applications.

Main Methods:

• One-step colloidal synthesis of three types of CDs (Type I, II, III) using different solvents.
• Characterization of CD properties including fluorescence, particle distribution, and agglomeration behavior.
• Assessment of CD cytocompatibility and cellular uptake in hMSCs.

Main Results:

• Type I CDs (citric acid, hexadecylamine, octadecene) were immiscible in culture media.
• Type II CDs (citric acid, octadecene) showed green fluorescence but agglomerated in hMSCs.
• Type III CDs (citric acid, deionized water) exhibited agglomeration-free behavior, a wide emission range (280-700 nm), low toxicity (threshold 1 mg/mL), and good hMSC cytocompatibility.
• Type III CDs demonstrated superior electrical conductivity and cytocompatibility compared to commercial graphene quantum dots.

Conclusions:

• The synthesis method and precursors significantly impact CD properties and biological interactions.
• Type III CDs offer a promising combination of fluorescence, electroactivity, low cytotoxicity, and good cytocompatibility.
• Type III CDs are suitable for bio-imaging, directional lineage commitment, and cell-based therapy.