Vaccine materials overview
The RaDVaC intranasal vaccine is very simple and consists of a small number of simple ingredients. The vaccine delivery vehicle is a water-soluble derivative of chitosan. Chitosan is a deacetylated form of chitin, which is found in mushrooms and the shells of crustaceans such as shrimp and crabs (seafood allergies are not allergies to chitin). Deacetylation produces free amino groups, and a high density of positive charges on chitosan. Chitosan is water insoluble at physiological pH, so we use a chitosan derivative that preserves positive charges and solubility across a wide range of pH conditions. A mildly acidic solution of chitosan is mixed with mildly basic and negatively charged triphosphate (sodium triphosphate, STP a.k.a. tripolyphosphate, TPP) under rapid stirring or vortexing. Ionically bonded chitosan gel nanoparticles form spontaneously upon mixing with TPP, including when mixed together with peptide. The method we use is adapted from published methods for creating peptide-loaded nanoparticles. You will find extensive documentation on all materials and methods in our White Paper, but for easier access and convenience, key materials and equipment are listed below.
Acquiring vaccine ingredients
All materials and ingredients are commercially available. Again, the vaccine is very simple and consists of the following ingredients: peptide(s), chitosan, sodium triphosphate, sodium chloride, and water.
- Epitope/antigen peptides. Multiple vendor options are available for synthetic peptides. These peptides are small synthetically produced portions of viral sequences.
- Water-soluble chitosan derivatives such as trimethyl chitosan and HACC.
- Sodium triphosphate, Na5P3O10. Multiple suppliers.
- Sodium chloride (NaCl). 5M stock solution.
- dH2O, deionized water (widely available).
- OPTIONAL: White vinegar and/or sodium bicarbonate (NaHCO3, baking soda) to adjust pH.
Preferred equipment and materials
Certain equipment is required for efficient vaccine production and administration. Vaccine can be produced without specialized laboratory equipment but the process is more laborious and the results are likely to be more variable.
- Pipettes: 1000 microliter, 200 microliter
- Sterile filtered pipette tips: 1000 microliter, 200 microliter
- Scale: gram scale accurate to 0.1 grams, or jeweler’s scale for very small amounts
- Clean spatula for dry reagents
- Small beakers for mixing and stirring. 10 ml to 25 ml beaker for stirring
- Small bottles for stock solutions; 100 ml to 250 ml
- 15 ml conical tubes
- 50 ml conical tubes
- 1.5 to 2 ml microcentrifuge tubes
- Stirring apparatus: magnetic stir plate and small stir bar to fit in beaker
- OPTIONAL but recommended: pH strips; range at least 2.0 to 9.0, but ideally from 0 to 10.0
- Nasal spray apparatus. These are available through multiple vendors. We selected small nasal spray bottles (about 5 milliliter) with a pump-top apparatus. A tube stem about 4 cm long and approximately 1 mm inner diameter extends from the bottom of the apparatus, which can be placed into the bottom of a 2-ml tube containing vaccine. Our spray apparatus delivers about 100 microliters per pump.
If you are ready to go deeper into details of the vaccine, click here the RaDVaC white paper.