When doing transfection, do the cell membrane's cationic and anionic faces affect the endosome for my reagent? I mean if my cells' membrane's outer face is cationic and my reagent outer face is anionic does that mean my transfection is going to fail? Is this true? And if it is, where can I learn the cell line's potential?
There are 3 major steps involved in gene delivery (and I hope this is what you mean with "transfection"). At first, you have have to form a NA/polymer-lipid-peptide-sugar complex. Second, interaction with the plasma membrane. Third, endosomal escape.
It is safe to say that in order to achieve complexation of the NA, you need a positively charged carrier. If you use lipids, the choice is sort of limited. DOTAP and SA are the most employed phospholipids in lipoplexes. You may also want to achieve endomal escape, and to do so you can use the classic DOPE/DOTAP or DOPE/CHEMS approach.
The point about interaction with the plasma membrane is kind of critical. In principle, if your formulation is properly designed and you are sure it is stable, the positively charged liposomal bilayer should interact with the negatively charged glycocalyx (if present) and this interaction MAY promote internalisation of the lipoplexes. On the other hand, if the formulation is lousy then the lipolexes may fall apart due to the loss of NA/lipid electrostatic interactions in favour of lipid/glycocalyx interaction. This occurs very rarely, though, so it is not a problem. If the plasma membrane is positively charged, which does not occur very often, then you lose the glycocalyx mediated internalisation and your lipoplexes should be seen as normal particles and follow any of the endocytic pathway.
You may also want to try to encapsulate NA in negatively charged liposomes, but I can assure you is not that easy and you still have the problem of achieving endosomal escape.
I'm doing siRNA trransfection with lipofectamine 2000 on HCT116 and HT29 colon cancer cell line. Where can i find if my cell line's positively or negatively charged? I heard that and i don't know if its necessary for the transfections. Thank you for your time and interest.
Lipofectamine should work regardless the surface charge.
All the best with your experiment
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