Everyone is familiar with DNA, or deoxyribonucleic acid, as the genetic material of our cells. Most people also know that DNA’s job is to act as the blueprint of the cell, containing genes that have instructions needed to make proteins that are essential to the survival of cells. However, there are instances where the DNA has mutated in people with important genes being inactivated or changed. This causes DNA to not synthesize important proteins needed for the cell’s survival. If this DNA is mutated in a majority of cells, the mutation can even lead to an affected person’s death. However, a recent innovation could be the solution to helping eradicate the possibility of fatalities and illnesses due to genetic problems.
Spherical nucleic acids, or SNAs, are composed of an inorganic core with covalently bonded genetic material sticking out of the core, giving it a sea mine-like appearance. And just like sea mines, the future of these SNAs is explosive. SNAs have the ability to cross the plasma membrane of cells with much greater ease than linear genetic material like DNA. This is due to the large density of genetic material located on the SNA, which can interact with special proteins called scavenger proteins on the plasma membrane of cells. This interaction causes the SNA to be “gripped” by the scavenger proteins and pulled inside the cell. Linear genetic material, like DNA, cannot interact with scavenger proteins, and so it’s a lot harder for them to enter the cell.
Because of the scavenger proteins, SNAs are able to get through the plasma membrane of cells and travel to the cell’s nucleus, where the cell’s own genetic material is stored. Because the SNAs have genetic material covalently bonded to the inorganic core, the SNA’s genetic material can combine with the cell’s genetic material, integrating the SNA’s genetic material into the cell. This can cause the cell to express whatever genetic material was on the SNA, which can be extremely useful for gene therapy. This could also potentially be used to cure genetic diseases, which is why SNAs are so innovative and exciting.
“But wait!” you might say. “Wouldn’t the SNA’s introduction to the body provoke an attack from the immune system?” Well, dear reader, you’re right. If the SNA only contained genes not originally from an organism’s genetic material, the immune system would mark the SNA as a foreign substance and try to destroy it. However, scientists have come up with a solution for this as well! And it involves a molecule called polyethylene glycol, or PEG.
In addition to having a pretty cool name, PEG has an even cooler chemical property: it is able to mask itself and whatever it’s attached to from the immune system! Because of this, substances with PEG attached to them are able to roam the body, staying relatively undetected by the immune system. If there ever was an award for best biological spy, it would definitely go to polyethylene glycol.
Overall, it’s safe to say that SNAs are a very promising way of changing genetic information in target cells without high risk. However, it’s important to note that they need to be used safely and for the right reasons; otherwise, it would be very easy to cause massive damage. So despite the bright future of SNAs, their production needs to be highly regulated. Because if it isn’t, and the wrong hands are given this promising molecule, immense amounts of pain and suffering could result.