In nanotechnology, nanoparticles are very small units or molecules usually 100 nanometers in diameter which are not joined together but exist independently. The main purpose of these particles in the biology is to use them for molecular imaging and for the delivery of therapeutic agents.
Gene therapy is one of many techniques which can be used to cure diseases either genetic or acquired by replacing damaged genes with the newly well functioned genes. Biomedical researchers think that this technique will be more effective if nanotechnology is mixed with this technique in the form of nanoparticles. Before using nanoparticles, gene therapy was performed with viruses as vectors by deactivating their own ability to cause the infections in the body. They would take the healthy genes in the body and replace the defected gene with it but still there were chances that viruses could retain their ability to cause infections or immune system might not accept those vectors. This would make the treatment more complicated for the researchers and doctors. Because of this, researchers have thought of introducing non-viral vectors in the gene therapy so that they themselves could not cause any infection in the body and could be accepted by the immune system easily.
International journal of Pharmaceutics has published a research recently that nanoparticles can be used to deliver genetic material into the cells without causing any or very little toxicity. This research has been carried out by the scientists of Ohio State University.
When doing experiments in the laboratory, the researchers had found out that the nanoparticles can be used as vectors to insert the foreign DNA into the cell and make it activated. This proved to be an important step in the improvement of gene therapy. The research also shows that this vector is works 1 times more efficiently than the other materials used as vectors because they make sure that the desired gene reaches its destination.
Creation of nanoparticle:-
Scientists created the nanoparticle by first making synthetic lipid which is placed in the solution containing calcium and phosphate. All three components combine together and as a result due to the change in the acidic properties, calcium phosphate creates a core. When the hard core is formed, then scientists mixed the desired DNA in the form of plasmid with this nanoparticle. All the things bundled together forming a nanoparticle which is now containing the foreign DNA.
How did scientists perform the experiment:-
To create a nanoparticle, scientists combined two ingredients together that is calcium phosphate and lipid shell. The positive point about combining these two ingredients is that they protect the foreign DNA on its way to the desired cell. When it enters the cell, the shell dissolves releasing the foreign DNA which replaces the defected DNA and makes the cell work in a normal way again.
Scientists used calcium phosphate and lipid shell to create nanoparticle because they are not harmful for the human body. The bones and teeth are made up of calcium. Similarly lipids are also useful components of the body as they are helpful in maintaining the structure of the cell membrane. But there is another point that if calcium phosphate is used alone, it is toxic for the cells and if only lipids are used they will get absorbed by the cells. But when they are combined together, they make a protective coating around the DNA and do not get it harmed by any component in the body. They dissolve only when they reach into the cell.
Zhou who is the author of this research at the Ohio University stated that the reason nanoparticles are used as vectors is that they have the self ability to dissolve and are acceptable by the immune system of the body also, unlike viral vectors which retain their ability to infect the cells and may cause other infections.
The same research was carried out by other researchers also. They used liposomes as nanoparticles. They are also the components of cell membrane. Though they also have the ability to dissolve in the cell but they are not good at releasing the desired gene into the cell. Similarly, if calcium phosphate is used alone as nanoparticle, due to its salty properties, it becomes large and cannot pass through the cell membrane of the desired cell. Immune system may also reject the calcium phosphate as a nanoparticle.
Scientists have plans to inject this particle along with the DNA into the cancerous cells that is why it is protected fully so that it cannot be digested by the other enzymes in the body on its way to the desired cell. To make their research more accurate, they performed an experiment on the serum. They exposed the particle to the serum, the DNA which had protective coating reached the destination while the exposed DNA was digested by the enzymes before reaching the desired cell.
Experiment on Mouse:-
Scientists used mouse as the experimental animal. They injected the DNA protected with the nanoparticle into the animal body and made it fluorescent so that it can be recognized. The DNA carried the gene code for protein with green fluorescent. They observed that the nanoparticle successfully entered the cell and after interactions with other components of the cell when it reached the desired target successfully, the green fluorescent protein lit up.
Scientists are planning to test the nanoparticle along with the DNA on animals. This research got the support of two institutes that is National Institute of health and National Science Foundation.
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