Moderna and Pfizer are using lipid nanoparticles that contain polyethylene glycol (PEG)2 for this purpose. The mRNA is wrapped in lipid nanoparticles (LNPs) that carry it to your cells, and the LNPs are “PEGylated” — that is, chemically attached to PEG molecules to increase stability.
This experimental mRNA gene therapy and its lipid nanoparticle-based delivery system have never been approved for use in a vaccine or drug. This includes Pfizer’s and Moderna’s COVID-19 vaccines, which were only “authorized” for emergency use by the U.S. Food and Drug Administration — not “approved.”
Significant concerns have been raised over the technology, including the lipid nanoparticles, and Moderna actually abandoned it in 2017 after studies revealed a high rate of adverse effects
[T]here can be no assurance that our LNPs will not have undesired effects. Our LNPs could contribute, in whole or in part, to one or more of the following: immune reactions, infusion reactions, complement reactions, opsonation reactions, antibody reactions . . . or reactions to the PEG from some lipids or PEG otherwise associated with the LNP. Certain aspects of our investigational medicines may induce immune reactions from either the mRNA or the lipid as well as adverse reactions within liver pathways or degradation of the mRNA or the LNP, any of which could lead to significant adverse events in one or more of our clinical trials.
https://sciencebasedmedicine.org/lip...o-antivaxxers/
https://pubmed.ncbi.nlm.nih.gov/24715289/
Superparamagnetic nanoparticle delivery of DNA vaccine
Fatin Nawwab Al-Deen 1, Cordelia Selomulya, Charles Ma, Ross L Coppel
Affiliations expand
PMID: 24715289
DOI: 10.1007/978-1-4939-0410-5_12
Abstract
The efficiency of delivery of DNA vaccines is often relatively low compared to protein vaccines. The use of superparamagnetic iron oxide nanoparticles (SPIONs) to deliver genes via magnetofection shows promise in improving the efficiency of gene delivery both in vitro and in vivo. In particular, the duration for gene transfection especially for in vitro application can be significantly reduced by magnetofection compared to the time required to achieve high gene transfection with standard protocols. SPIONs that have been rendered stable in physiological conditions can be used as both therapeutic and diagnostic agents due to their unique magnetic characteristics. Valuable features of iron oxide nanoparticles in bioapplications include a tight control over their size distribution, magnetic properties of these particles, and the ability to carry particular biomolecules to specific targets. The internalization and half-life of the particles within the body depend upon the method of synthesis. Numerous synthesis methods have been used to produce magnetic nanoparticles for bioapplications with different sizes and surface charges. The most common method for synthesizing nanometer-sized magnetite Fe3O4 particles in solution is by chemical coprecipitation of iron salts. The coprecipitation method is an effective technique for preparing a stable aqueous dispersions of iron oxide nanoparticles. We describe the production of Fe3O4-based SPIONs with high magnetization values (70 emu/g) under 15 kOe of the applied magnetic field at room temperature, with 0.01 emu/g remanence via a coprecipitation method in the presence of trisodium citrate as a stabilizer. Naked SPIONs often lack sufficient stability, hydrophilicity, and the capacity to be functionalized. In order to overcome these limitations, polycationic polymer was anchored on the surface of freshly prepared SPIONs by a direct electrostatic attraction between the negatively charged SPIONs (due to the presence of carboxylic groups) and the positively charged polymer. Polyethylenimine was chosen to modify the surface of SPIONs to assist the delivery of plasmid DNA into mammalian cells due to the polymer's extensive buffering capacity through the "proton sponge" effect.