Polyethylenimine-Modified Fluorescent Carbon Dots As Vaccine Delivery System for Intranasal Immunization

Area of Science:

• Biomedical Nanotechnology
• Vaccinology
• Immunology

Background:

• Fluorescent carbon dots (CDs) are luminescent nanomaterials gaining attention in biomedicine.
• Their unique optical properties and nanoscale size make them suitable for advanced applications.
• Developing effective vaccine delivery systems is crucial for enhancing immunization strategies.

Purpose of the Study:

• To develop and evaluate fluorescent carbon dots (CDs) as a novel vaccine delivery system for intranasal immunization.
• To assess the immunogenicity and antigen-tracking capabilities of CDs when used for delivering model protein antigens.

Main Methods:

• Polyethylenimine-modified CDs were synthesized using a microwave-assisted method.
• Intranasal immunization was performed using CDs as carriers for the model protein antigen ovalbumin.
• Immune responses, including antibody titers, cytokine secretion, and cell proliferation, were analyzed.

Main Results:

• CDs significantly enhanced IgG and IgA induction at mucosal sites.
• Splenocyte proliferation and interferon-gamma (IFN-γ) secretion were notably increased.
• The study demonstrated the capacity of CDs to trace antigen transport from the administration site to lymph organs.
• Enhanced generation of memory T cells was observed.

Conclusions:

• Fluorescent carbon dots (CDs) serve as an effective intranasal vaccine delivery system.
• CDs enhance mucosal and systemic immune responses, including the generation of memory T cells.
• The inherent fluorescence of CDs allows for visualization and tracing of antigen transport, offering insights into vaccine delivery mechanisms.