Topical vaccination with super-stable ready to use nanovesicles

Area of Science:

• Nanotechnology
• Vaccinology
• Biochemistry

Background:

• Ultradeformable archaeosomes (UDA) are nanovesicles derived from archaea, recognized for topical vaccination.
• Pharmaceutical applications require UDA to withstand sterilization and lyophilization (SLR-UDA) for extended shelf life.
• The adjuvant capacity and antigen formulation of SLR-UDA remain unexplored.

Purpose of the Study:

• To evaluate the adjuvant potential of SLR-UDA.
• To investigate the impact of antigen physical mixing versus encapsulation within UDA.
• To assess the stability of UDA during pharmaceutical processing.

Main Methods:

• Preparation of UDA from total polar archaeolipids (TPA), soybean phosphatidylcholine, and sodium cholate.
• Sterilization and lyophilization of UDA, with optimization using glycerol and glucose.
• Topical administration of SLR-UDA with ovalbumin (OVA) to Balb/c mice.
• Measurement of anti-OVA IgG titers and assessment of immune responses (Th2, cell-mediated).

Main Results:

• UDA exhibited high stability during heat sterilization and storage at 40°C for 5 months.
• Lyophilization required glycerol and glucose addition for UDA stability.
• SLR-UDA induced comparable anti-OVA IgG titers to fresh UDA.
• Physical mixing of OVA with SLR-UDA yielded similar Th2-biased and cell-mediated responses as encapsulated OVA.

Conclusions:

• Total polar archaeolipids (TPA) are crucial for UDA's super-stability, conferring resistance to sterilization and cold-free storage.
• SLR-UDA serves as a ready-to-use topical adjuvant, simplifying manufacturing and reducing costs.
• This research paves the way for more accessible and stable topical vaccine formulations.