AMPHIPOLS: Biomedical Applications
Vectorization.
APols keep various hydrophobic peptides soluble suggesting that they can be used as solubilizing and vectorizing agents. An analysis has been undertaken of the biodistribution of APol-trapped transmembrane peptides applied to COS cells (Popot et al. (2011)).
The biodistribution and elimination of A8-35 were followed using fluorescent amphipols (dyes: Alexa647 and rhodamine) with in vivo fluorescence imaging on mice. Three injection routes were chosen: intravenous (IV), intraperitoneal (IP), and subcutaneous (SC) and an interesting observation is the acccumulation of A8-35 in fats pads that could be used for the delivery anti-obesity drugs (Fernandez et al (2014)).
Figure 14. Using amphipols to deliver transmembrane peptides to cells and tissues (Popot et al. (2011))
Figure 15. Biodistribution of amphipol fonctionnalized with Alexa647 dye (FAPolAF647) following subcutaneous injection (SC)(Fernandez et al (2014)).
Vaccination.
APols present a number of properties that make them intriguing candidates to improve MP-based vaccines. Initial experiments have been carried out using as an immunogen the major outer MP (MOMP) from Chamydia trachomatis, a trimer of β barrels. Upon vaccination, protection against an intranasal challenge with live C. trachomatis is considerably improved in mice that have received A8-35-trapped MOMP, reaching levels comparable to those observed following a previous exposure to the live bacterium ( Tifrea et al. (2011) ).
Figure 16. Assessing the protection afforded by MOMP/APol vs. MOMP/detergent vaccines (Tifrea et al. (2011)).
Diagnostic.
Trapping MPs with an APol functionalized with biotin results in the formation of stable complexes that can be immobilized onto surfaces coated with streptavidin. This opens the way to an extremely wide range of applications (Charvolin et al. (2009)): study of protein/ligand interactions (antibodies, natural biological partners), drug screening, diagnostics, creation of biosensors...
