Invivo delivery of siRNA through the use of nanoparticles

Cells are the building block of life. They live everywhere, and interact with everything to react or adapt to their surroundings and environment. It is without surprise that scientist have gone out of their way o see how these fundamental bodies of life work. A piece of this question is answered by DNA, RNA, ribosomes, and protein production, and how they interact with each other. When we look at protein production, everything starts with the instructions that the DNA tells the cell to carry out. 

The DNA will send messenger RNAs (mRNA) out of the cell, and they in turn will find a ribosome to attach to, and it will tell the ribosome what to do. The primary job of ribosomes is protein production. One could look at ribosomes as a translator of what the boss wants to the language of the workers. The workers in this case, are the organelles, who cannot understand the genetics code of the genome. The organelles speak and act with proteins, so they do what the ribosome's proteins tell it to do. (Source)

Therefore, we see that the expression of the DNA is intimately reliant on proteins being expressed - or lack thereof - in the correct amounts. Biologist today are finding ways on controlling which genes are being expressed by altering which RNAs's instructions reach the cell. SiRNAs (short interfering RNA) are a type of RNA that allow us to "knock-down" genes. This is to say, we keep them from being expressed. 

This is so ground breaking because now we can suppress what a gene says This thus has obvious applications for cancer and other genetic maladies. 

RNAs are only slightly larger than the nanoscale in size (~300nm, where nanoscale is 1-100nm). The real nanotechnology being used is the method of delivery. For the siRNAs to be most useful, they need to injected into the cell. This problem was solved using what is called interfering nanoparticles, of iNOPs. These are made with a small natural polymer called poly-L-lysine, which had positively charged residues. As it happens, siRNA molecules are negatively charged, with means the two would stick together until they got into the cell. At this point, the cell naturally breaks the bond between the two, causing the siRNAs to be released into the cell to silence the undesired gene. (Source)

Resource: NanoCellBiology

"The 400-page book discusses novel approaches and applications that have unraveled a new understanding of the cell and its impact on biology, medicine and health care. The book, according to the publisher, is intended to familiarize readers with major developments in the field of nanotechnology, novel imaging methods and new discoveries related to understanding the cell.The book also provides a comprehensive understanding of the discovery of a new cellular structure identified as the porosome. Discovered by Jena 15 years ago, the porosome is the universal secretory machinery in cells. Secretion is a fundamental cellular process that occurs in all living organisms. Cell secretion is responsible for numerous activities, including neurotransmission and the release of hormones and digestive enzymes. Secretory defects are responsible for a number of debilitating conditions, including growth defects, diabetes and neurological disorders.Jena's work has focused primarily on the molecular machinery and mechanism underlying cell secretion. His discovery of the porosome has revolutionized understanding of the secretory process in cells. He and his team have further determined the structure and dynamics of the porosome, its isolation and composition, and its functional reconstitution in lipid membrane. His studies demonstrate for the first time that, following a secretory stimulus, membrane-bound secretory vesicles transiently dock and fuse at the base of porosomes present at the cell plasma membrane to release intravesicular contents as opposed to the commonly held belief that during cell secretion, secretory vesicles completely merge and collapse at the cell plasma membrane. His discoveries explain the presence of partially empty secretory vesicles in cells following secretion." Nanowerk News

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