Poly[di(carboxylatophenoxy)phosphazene] is a potent adjuvant for intradermal immunization.

Area of Science:

• Vaccinology
• Biomaterials Science
• Immunology

Background:

• Intradermal immunization with microneedles offers enhanced immune responses and antigen sparing.
• Current microneedle technology faces limitations with common adjuvants like alum.
• Solid vaccine formulations for microneedles can improve shelf-life.

Purpose of the Study:

• To introduce a novel polyphosphazene immuno-adjuvant (PCPP) for microneedle-based intradermal immunization.
• To evaluate PCPP's function as both an adjuvant and a microfabrication material.
• To assess the efficacy of PCPP-coated microneedles for hepatitis B surface antigen delivery.

Main Methods:

• Development of poly[di(carboxylatophenoxy)phosphazene] (PCPP) as a microneedle coating.
• Intradermal delivery of hepatitis B surface antigen using PCPP-coated microneedles in pigs.
• Comparison of immune response and antigen sparing with intramuscular administration.

Main Results:

• PCPP-coated microneedles demonstrated superior immune activity in pigs compared to intramuscular delivery.
• Significant antigen sparing potential was observed with the PCPP microneedle system.
• PCPP accelerated microneedle fabrication and reduced reliance on surfactants.

Conclusions:

• PCPP is a potent immuno-adjuvant and microfabrication material for intradermal immunization.
• PCPP-coated microneedles offer an effective strategy for adjuvanted vaccine delivery via patches.
• This technology holds promise for improved vaccine administration and efficacy.