As pharmaceutical field is emerging day by day and in order to produce vaccines there are certain ways for vaccine developers which are as following like one is using virus itself and reduce its virulence rendering it harmless and insert it into the body which will initiate the body’s immune response system and develop the defense against that virus which is a very slow process and take huge budget in research and development and this is known as “Attenuated (weakened) virus vaccine”. Second is of creating vaccines using a particle or a fragment of viruses like the spike proteins and using DNA recombinant technology insert that gene into a vector or a body to attain the immune defense which is known as “Subunit Vaccine” which is also a very slow process to develop vaccines, for example, scientists wanted to create a vaccine for Novel Corona Virus COVID-19. The quicker way to create a vaccine is to take RNA fragments from virus and create copies of viral RNA and insert directly into the body but there’s a problem in this process like RNA lack the ability to cross the cell membrane and there are ribonucleases which are normally found in the body and cleave the RNA so there come the lipid nanoparticles.
Lipid nanoparticles are minute particles having a size of about 30-200 nanometers. These tiny bubbles are made up of water and lipids, inner water and outer lipid bilayer. The benefit of using lipid nanoparticles is to transport viral RNAs and protect them from the ribonucleases and allow their passage through the cell membrane. They can be inserted via syringe into the body via intramuscular or subdermal route and then taken by antigen-presenting cells like dendritic cells or B-cells by endocytosis. The endosomal membrane and lipid bilayer merge and help in the release of RNA package. Then viral RNAs produce viral protein using ribosomes and cleaved by proteasomes and these protein particles are processed in the endoplasmic reticulum to make “MHC” which presented to CD4T Killer cells to develop the body’s immunity.
These lipid nanoparticles can be decorated which other substances like ligands to target specific cells in the body and boost the immunity process which was not possible without the lipid nanoparticles due to the lack of transport system for RNAs. Using lipid nanoparticles increase the speed of vaccine production due to its ability to transport RNA to the cells.