Biodegradable scaffolds for enhancing vaccine delivery

Area of Science:

• Biomaterials Science
• Immunology
• Vaccinology

Background:

• Sustained release of vaccine components can improve efficacy over traditional bolus injections.
• Biodegradable scaffolds offer potential for controlled delivery of antigens and adjuvants.

Purpose of the Study:

• To develop and evaluate a hyaluronic acid (HA) cryogel scaffold for sustained delivery of vaccine components.
• To assess the immunogenicity and therapeutic potential of the HA cryogel formulation (CpG-OVA-HAC2) in preclinical models.

Main Methods:

• Fabrication of a biodegradable HA-scaffold (HA cryogel) for in vivo vaccine delivery.
• Assessment of subcutaneous injection of HA cryogels for antigen and adjuvant release.
• Evaluation of immune responses (antibody and T cell) and therapeutic efficacy in immunodeficient and melanoma mouse models.

Main Results:

• The HA cryogel mediated sustained antigen and adjuvant release, inducing a durable immune response.
• CpG-OVA-HAC2 formulation enhanced immune response while minimizing inflammation.
• Dose escalation studies showed dose-dependent antibody and T cell responses.
• CpG-OVA-HAC2 elicited significantly higher antibody responses than bolus injection in immunodeficient mice.
• In a melanoma model, CpG-OVA-HAC2 demonstrated prophylactic protection, slowed tumor growth, enhanced survival, and induced immunological memory.

Conclusions:

• The developed HA cryogel scaffold is a promising platform for sustained vaccine delivery.
• CpG-OVA-HAC2 formulation enhances vaccine efficacy, offering potential for improved cancer immunotherapy and long-lasting protection.