Transfection
Transfection, which is the process of introducing foreign nucleic acids into host cells, is one of the most powerful molecular biology tools currently in use. As the exogenous DNA or RNA becomes functional in the transfected cells, they exhibit specific behavior otherwise not demonstrated by normal cells. The technology is extensively used in studying gene expression, cellular events, developing drugs, designing knockout systems, and testing novel therapeutic strategies.
Scientists typically utilize transfection reagents to help with insertion of DNA or RNA into cancer cell lines. Specific transfection reagents are used for different types of cells in vitro. In vivo nanoparticle-based transfection reagents have been recently developed for delivery of DNA, siRNA and microRNA molecules to xenograft animal models.
Nucleic acid based products, including miRNA, siRNA, and gene constructs make short hairpin RNA (shRNA) notorious for being difficult to deliver to cells. shRNA is known for often being excreted from cells prior to exhibiting functional effectiveness. Nucleic acids are vulnerable to nucleases in the blood and the gastrointestinal system. Nanocarriers face a variety of different delivery tasks and physiological environments. Solutions to this problem are continually under investigation for new polymeric nanoparticles, liposomal nanoparticles, liposomal formulations, and viral vectors. Nanocarriers can be designed and produced in specific ways to match the goal of the experiment. Nanoparticle-based transfection reagents are an emerging product in this area to ensure a high efficiency transfection system.
Nanoparticle based Transfection
In spite of the array of transfection reagents already available on the market today, researchers find delivery of external nucleic acids particularly difficult and there is a need for nanoparticle based transfection delivery systems.
Some cells are relatively easy to transfect, whereas others, such as stem cells, suspension cells, or primary cells show poor transfection results. This is where nanoparticles, each behaving as a single unit, come into the play. Owing to their ultra-miniaturized size (ranging from 1 to 100 nanometers), nanoparticles are being utilized intensely in today’s research. Nanoparticles hold the promise of applications in the field of biomedicine, and especially siRNA transfection for RNAi therapeutics.
Due to the immense therapeutic application of DNA and RNA transfection, especially in cancer treatment, many laboratories are using nanotechnology to come up with nanoparticle based reagents to deliver their payload. Experiments have proven nanoparticles to be efficient vehicles in transporting exogenous nucleic acids into cells.
Silica nanoparticles function by concentrating complexes of transfection reagent molecules and nucleic acid chains on the cell membrane. Silica nanoparticles in combination with cationic transfection reagents have been shown to enhance transfection efficiency rates. For example, DNA attached to gold nanoparticles can transfect into cells, so long as special chains are also present on the nanoparticle.
Nanoparticle Considerations
Although nanoparticles can be efficient at transfecting DNA into cell cytoplasm, their efficiency at transporting nucleic acids into the nucleus is far more suspect. As a result of internal cell processing and machinery, the nanoparticles may not make it into the nucleus. Additionally, certain nanoparticles may damage cells, leading to cytotoxicity. These effects may be limited by using appropriate transfection reagents, which can improve the chances of cell survival and membrane reformation.
Nanoparticles have so far been experimental, although current research suggests they may be highly effective at transporting shorter length nucleic acid chains.
The trade-offs with using nanoparticle transfection methods can be seen in several studies. AuNPs (gold nanoparticles) have been the topic of interest, primarily due to their affinity for biomolecules when charged and their chemical stability. The Duran et al. 2011 research paper investigated AuNPs and found that plasmid DNA vectors transfection efficiency is significantly increased when AuNPs are added alongside conventional transfection reagents. However, there was also an increase in cytotoxic effects and decreased cell proliferation.