Is there any possibilities or perhaps anyone have ever heard or read about it in any journals? The information would be very helpful for my research. Thank you.
I have not heard of this at all. The closest thing would be when they inject naked plasmid hydrodynamically in vivo, but I have not seen an analogous experiment done in vitro.
The possibility will likely vary between cell types, but you can expect efficiency to be low.
In general, it would seem unlikely that negatively charged nucleic acids (e.g. plasmids) would readily interact with negatively charged cell membrane. However, nucleic acids may interact with other biomolecules (unintentional vectors), possibly making them more likely to be taken up by cells. Even if taken up (endocytosed), there is then the issue of whether the plasmid will enter the nucleus and whether the transgene will be expressed. The known limitations are what prompted the development of viral and non-viral vectors, and techniques such as electroporation and gene guns.
"Wolff and co-workers were the first to show that simple application of naked DNA is sufficient for gene transfer leading to the expression of the transgene [12]." http://www.ncbi.nlm.nih.gov/pubmed/14978750
Uptake by cells is not the only necessary step for transgene expression: "Plasmid DNA microinjected into the nucleus results in high expression levels, whereas plasmid DNA injected into the cytoplasm is only poorly expressed. Pollard et al. observed that only 0.1% of naked DNA or 1% of polymer-complexed DNA reached the nucleus of COS-7 cells following microinjection into the cytoplasm." [http://www.ncbi.nlm.nih.gov/pubmed/16525863]
I routinely use plasmids (without vectors) as controls for my nanoparticle-mediated plasmid delivery. I have never seen a transfected cell in any control culture (primary oligodendrocyte precursor cells (OPCs), oligodendrocytes and astrocytes).
Right now I'm actually trying to find an economically-friendly method of delivering antiviral plasmid to Artemia (brine shrimp) which later will be fed to shrimp larvae. Since Artemia is too small (only less than 0.4in in size) I can't inject the plasmid. The only way is by incubating it in plasmid solution. But to encapsulate the plasmid with what reagents, I still have no idea (since most reagents are too expensive to be commercially-used in shrimp farm).
Thank you for your helpful answers, I really appreciate them. Have a nice day!
You could try calcium phosphate precipitation. There are tons of protocols online (a paper can be found at http://nar.oxfordjournals.org/content/24/4/596.long) and this is a very cheap way of transfecting plasmid. I have no idea if it will work on your brine shrimp, or if it will be compatible with your media, but its cheap, easy and worth a try.
Do you want the plasmid to remain intact in the Artemia, then be ingested by the larvae? Does the plasmid contain a transgene encoding an antiviral protein?