I'm working on phosphotidylcholine vesicles as drug carrier to deliver plant extracts and desire to test the cell internalization of these vesicles into skin cells.
Can you suggest suitable probes for phosphotidylcholine vesicles and call membrane fusion/ internalization?
Well, you can load the vesicle with high concentrations of an aqueous self-quenching fluorophore such as fluoresceine (see Molecular Probes Handbook), or you can use dyes (such as DiI dyes, DiD, DiO, DiI,... ) in the membrane, you can even choose an efficient FRET pair so you can see the dilution as the disappearance of FRET while individual fluorecences remain so that quenching can be excluded.
If you wish to suggest clinical use of those, I am afraid, though, that the reviewers will say that it is of no interest if the vesicles are internalized in cultured keratinocytes unless you show first that they can penetrate stratum corneum. Wound healing is the only exception, so better to concentrate on that, if they do not penetrate the skin otherwise. Unless you plan to given them intravenously.