Phospholipid Bilayer-Coated Aluminum Nanoparticles as an Effective Vaccine Adjuvant-Delivery System

The <i>p</i>hospho<i>l</i>ipid bilayer-coated <i>a</i>luminum <i>n</i>anoparticles (PLANs), formed via chemisorption, were prepared by reverse ethanol injection-lyophilization (REIL) utilizing the phosphophilicity of aluminum. The anhydrous antigen-loaded PLANs obtained by REIL proved stable, satisfying using the controlled-temperature-chain instead of the integrated cold-chain for distribution, and could be rehydrated to reconstitute instantly an aqueous suspension of the antigen-PLANs, which were more readily taken up by antigen-presenting cells and, when given subcutaneously to mice, induced more robust antigen-specific humoral and cellular immunoresponses but less local inflammation than the antigen-alum. Thus, the PLANs are a useful vaccine adjuvant-delivery system with advantages over the widely used naked alum