Mymetics Corp (MYMX)

[TheHungryHippo]

Advantages of Virosomes:

Virosomes are biodegradable, biocompatible, and non-toxic 13
Virosome technique is approved by the FDA for human use with a high safety profile.No risk of disease transmission
No chances of autoimmunogenity or anaphylaxis 18
Capable of delivering the drug into the cytoplasm of target cell
Broadly applicable to anticancer drugs, proteins, peptides, nucleic acids, antibiotics, fungicides)
Provides protection to drugs from degradation
Promotes fusion activity in the endolysosomal pathway

Characterization of Virosomes:
Detection of protein: sodium dodecyl-sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) can confirm the presence of HA protein in the virosomes 19.
Fusion activity: virosomes exhibit pH-dependent membrane fusion activity similar to native influenza virus and can be visualized with a fluorescent resonance energy transfer assay (RET) 18. Fusion activity can also be monitored indirectly by determining hemolytic activity, which indirectly corresponds to fusion activity and shows pH dependence similar to that of fusion 11.
Structure and size: Negative-stain electron microscopy generally used to determine ultrastructure and size of virosomes. The staining solution is of neutral pH, to avoid acid-induced conformational changes of HA 20.

Virosome Structure: Virosomes are spherical unilamellar vesicles with a mean diameter of around 150 nm. Influenza virus is most commonly used for virosome production.
Virosomes cannot replicate but are pure fusion-active vesicles. In contrast to liposomes, virosomes contain functional viral envelope glycoproteins: influenza virus hemagglutinin (HA) and neuraminidase (NA) are intercalated within the phospholipid bilayer membrane.
Further characteristics of virosomes depend on the choice of bilayer components. Virosomes can be optimized for maximal incorporation of the drug or for the best physiological effect by modifying the content or type of membrane lipids used. It is even possible to generate carriers for antisense-oligonucleotides or other genetic molecules, depending on whether positively or negatively loaded phospholipids are incorporated into the membrane.
Various ligands, such as cytokines, peptides, and monoclonal antibodies (MAbs) can be incorporated into the virosome and displayed on the virosomal surface. Even tumor-specific monoclonal antibody fragments (Fab) can be linked to virosomes to direct the carrier to selected tumor cells 21.



http://ijpsr.com/bft-article/virosomes-a-novel-vaccination-technology/?view=fulltext