Self-assembled Ac-FFA-NH₂ based hydrogels with strong immunostimulating activity for vaccine delivery

Area of Science:

• Biomaterials Science
• Immunology
• Vaccine Development

Background:

• Peptide self-assemblies are emerging as effective vaccine adjuvants.
• The Ac-FFA-NH2 peptide gelator is a biocompatible material previously explored for tissue engineering.

Purpose of the Study:

• To evaluate the Ac-FFA-NH2 hydrogel as a vaccine delivery system.
• To investigate the immunomodulatory effects and immune response enhancement of the Ac-FFA-NH2 hydrogel.
• To develop and characterize a composite hydrogel of Ac-FFA-NH2 and liposomes.

Main Methods:

• In vivo vaccination studies using ovalbumin (OVA) antigen incorporated into the Ac-FFA-NH2 hydrogel.
• Measurement of IgG titers and IgG2a subtype production to assess humoral and cellular immune responses.
• Structural and morphological characterization of the composite hydrogel using Transmission Electron Microscopy (TEM), Differential Scanning Calorimetry (DSC), and Fourier-Transform Infrared Spectroscopy (FTIR).

Main Results:

• The Ac-FFA-NH2 hydrogel significantly increased IgG titers compared to unadjuvanted controls and traditional adjuvants.
• The hydrogel induced a robust humoral immune response and stimulated a cellular immune response, evidenced by IgG2a production.
• A composite hydrogel of Ac-FFA-NH2 and liposomes was successfully developed, retaining structural integrity and mechanical robustness.

Conclusions:

• The Ac-FFA-NH2 hydrogel is a potent vaccine delivery platform that effectively enhances both humoral and cellular immunity.
• The composite hydrogel maintains structural integrity and mechanical properties, offering potential for advanced vaccine formulations.
• Ac-FFA-NH2 hydrogels represent a promising strategy for developing next-generation vaccines with improved efficacy.