Magnetic nanoparticles in Gene therapy

          The transfection of the suitable genes into cells is the primary target of gene therapy. Earlier the genes are trasfected by binding with gold nanoparticles and injecting by a transfection gun. Later the electroporation technique is used where the small electric voltage is applied which increases the permeability of the cell  which leads to intake of more genes of interest. Recently, the use of magnetic nanoparticles is rapid in studying the gene delivery mechanism for various diseases and various kinds of genes of interest. The delivery of genes has to overcome the barriers of the skin if it is transfected externally or if to the brain it has to cross the blood-brain barrier (BBB) a key rate limiting step in the drug/gene delivery to brain. People employ mostly liposomes for brain drug delivery as they easily pass the BBB. Several researchers are trying to get the correct carrier with proper mechanism to have a successful gene transfection. Companies like Nano Therics (www.nanotherics.com) are provinding various instruments for gene transfection by magnetic nanoparticles. 

          For the recent news on gene delivery using magnetic nanoparticles, the readers are directed to the following link http://www.sciencedaily.com/releases/2013/05/130530111153.htm. Eventhough the research progresses, still there is much to go. 

The Power of Magnetic Nanoparticles as Detection Agents of Single Bacteria

 Nanotechnology based detection assays are not new within the last decade. A variety of unique strategies are being tried by various researchers around the world to identify the pathogenic bacteria using magnetic nanoparticles. 

 A recent paper published in nature nanotechnology reports the detection of a single pathogenic bacteria using DNA sandwich hybridization technique where the target DNA (analyte) is being sandwiched by the DNA attached to the magnetic nanoparticles. Here, the corresponding author Ralph Weissleder, a pioneer scientist and doctor, used polymeric nanoparticle conjugated with magnetic nanoparticles as magnetic beads which hosted the complementary DNA sequences to the target bacterial 16S ribosomal sRNA. The micro NMR is being used as the detection system. The micro NMR is the actual NMR which is fabricated to the micron size holds a sample of ~ 2 micro liters. The detection sensitivity of the bacterial RNA sequences were checked and validated over 13 pathogenic bacterial species. They claim that the system is robust in detection of pathogenic bacteria with high sensitivity. Besides, the same approach can be used to identify the unknown bacteria by employing the target specific primers attached to the magnetic beads. This is a dual approach for a single nanopaticle system.

The pros of this work are that they developed and validated an RT-PCR based bacterial detection assay with low sensitivity and high specificity.

The cons of this work are the cost issues where the procuring of the primer sequences and RT-PCR with all the enzymes are costly will be a non possible one except in very high infrastructure hospitals or clinics.

The article was studied from http://www.nature.com/nnano/journal/v8/n5/pdf/nnano.2013.70.pdf

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