Antigen-decorated shell cross-linked nanoparticles: synthesis, characterization, and antibody interactions

Area of Science:

• Nanotechnology
• Materials Science
• Immunology

Background:

• Developing nanoscale platforms for biological applications requires precise control over surface presentation of functional groups.
• Mimicking viral structures can offer insights into multivalent interactions with biological targets.

Purpose of the Study:

• To synthesize and characterize antigen-decorated shell cross-linked knedel-like nanoparticles (SCKs).
• To investigate the multivalent presentation of antigens on SCKs for antibody binding and biological response.

Main Methods:

• Amphiphilic diblock copolymers with specific antigen (2,4-dinitrophenyl) or control groups were synthesized via atom transfer radical polymerization.
• Micelles were formed and their coronas cross-linked to create SCKs with controlled dinitrophenylation levels.
• Nanoparticle characterization included dynamic light scattering, electron microscopy, atomic force microscopy, and various spectroscopic techniques.
• Antibody binding and cellular response were assessed using IgE antibody quenching titrations and RBL-2H3 cell degranulation assays.

Main Results:

• Shell cross-linked knedel-like nanoparticles (SCKs) were successfully fabricated with tunable dinitrophenyl (DNP) antigen density.
• Characterization confirmed the formation of stable nanoparticles with surface-available DNP groups.
• DNP-SCKs demonstrated effective multivalent binding with IgE antibodies.
• This binding triggered the degranulation of IgE-sensitized RBL-2H3 cells.

Conclusions:

• Antigen-decorated SCKs serve as effective multivalent nanoscale surfaces for antibody presentation.
• The synthesized DNP-SCKs can mimic viral surface properties for biological interactions.
• These nanoparticles show potential for applications in immunology and nanomedicine.