Saturday 27 July 2019

Electroporation: How it helps towards the betterment of medical science?

­Electroporation is an electrical technique that involves the application of high-voltage electric pulses for a very short duration to enhance the skin permeability reversibly, for macromolecules. It is a powerful transfection tool which is useful for studying gene function. It actually focused on the vertebrate tissues and organisms, recent work demonstrated the efficacy of this tool for delivering RNA into tick eggs. Electroporation permeabilizes the membranes of cells. When an electrical current is applied. The long RNA is usually delivered in a high ionic strength medium. This process requires consideration of factors including tick developmental stage, RNA does, electrode design, electrical field, and duration. It is a useful method for delivering long RNA into immature tick stages. It is a technique that is also being investigated for RNA delivery in tick eggs.  Ease of electroporation for gene silencing in the tick egg stage would make RNA more widely. It is available for biologists and future RNA applications in tick–host-pathogen interaction and high-throughput tick functional genomic research. It is a transformation technique that uses induction uptake by exposing cell walls to high-intensity electrical field pulses.

Electroporation is performed with the purpose-built appliances which create an electrostatic field in a cell solution. The cell suspension is conveyed into a glass or plastic which has two aluminum electrodes on its sides. For bacterial Electropermeabilization, a suspension of around 50 microliters is used. This suspension of bacteria is mixed with the plasmid and then ready to be transformed. The success of the Electropermeabilization depends on the salt content and purity of the plasmid solution. 

In vivo gene, electrotransfer was first described in and now there are many preclinical studies of gene electrotransfer. The method is used to deliver a large variety of genes for the potential treatment of several diseases. Disorders in the immune system, tumors, metabolic disorders, cardiovascular diseases, monogenetic diseases, analgesia are such reasons.

Uses of Electroporation in the field of Medical Science:

The first medical application was used for introducing poorly anticancer drugs into tumor nodules. Soon also gene electro-transfer became of special interest because it is low cost, easiness of realization and safety. Viral vectors can have serious limitations and pathogenicity when used for DNA transfer.


Electroporation is based on a very simple process. Host cells and selected suspended and molecules are in a conductive solution, and an electrical circuit is closed around the mixture. An electrical pulse at only lasting a few microseconds and an optimized voltage and to a millisecond is discharged through the cell suspension. This disturbs the phospholipid layer of the membrane and results in the formation of temporary pores. The electric potential all across the cell rises to allow the charged molecules like the DNA to drive throughout the pores in a manner similar to the electrophoresis. The main advantage is its applicability for transient and stable transfection of all cell types. Electropermeabilization is a process that is easy and rapid and that’s why it is able to transfect a large number of cells in a short time once optimum conditions are determined. The major drawback is substantial cell death caused by high voltage pulses and the only partially successful membrane repair. Requiring the use of huge quantities of cells compared to chemical transfection methods. Instrumentation overcomes high cell mortality by distributing the electrical pulse equally among the cells. It maintains a stable pH, optimization of pulse and field strength parameters that are still required to balance the electroporation efficiency and cell viability.

Electroporation permits the cellular outline of large highly charged molecules as DNA which cannot diffuse passively across the hydrophobic bilayer core. This indicates the machine is the creation of nm-scale water-filled holes in the membrane. Although dielectric breakdown and electroporation both result from the application of an electric field, the mechanisms are involved fundamentally different. In dielectric breakdown the material is ionized, creating a conductive pathway. The material alteration is chemical. The lipid molecules shift instead of chemically altered of their position in electroporation and it opens a pore which performs as the conductive pathway through the bilayer as it is filled with water.

Electroporation is an active phenomenon that relies on the local transmembrane voltage at each point. It is generally a specific trans-membrane voltage threshold that exists for the manifestation of the electropermeabilization phenomenon. This leads to the definition of an electric field magnitude entry for electropermeabilization. That is, only the cells within areas are electroporated. If a second entry is reached or surpassed, this process will compromise the viability of the cells.

Electroporation is a multi-step process with several well-defined phases. At first, a short electrical pulse must be applied. The typical parameters would be 300–400 mV for < 1 ms across the membrane. Once the critical field is achieved then there is a rapid localized rearrangement in lipid morphology. Since it is not electrically the resulting structure is believed to be a "pre-pore".  Conductive but leads are rapid to the creation of a conductive pore. Proof for the existence of such pre-pores comes mostly from the "flickering" of pores, which suggests a transition between insulating and conductive states. It has been suggested that these pre-pores are smaller.

Here we discuss some of the advantages and disadvantages of Electroporation:-

Advantages:
  1. It is very effective with nearly all cells and space types.
  2. A large number of cells taking in the target DNA and molecule.
  3. The amount of DNA required that is smaller than for other methods.
  4. The procedure VIVO may be performed with intact tissue.

Disadvantages:
  1. Poor flexibility and control of parameters in low cell survival.
  2. Amplitude drop during the pulse low amplitude flexibility.
  3. Complex switching elements required impedance matching.
  4. Complicated design low output power.

Tuesday 16 July 2019

The fields in which we can use Optical fiber cables for better transmission


Optical fiber, thin flexible fiber with a glass core via which light signals can be sent with minute loss of strength. This Optical fiber is also transparent. Optical fibers are mostly used in transmit light between the two ends of the fiber and find wide usage in fiber-optic communication. Here they permit transmission over longer distances and at higher data rates than electrical cables. Fibers are used instead of metal wires because signals travel along with them with less in addition. Optical fibers are also used for illumination and imaging. These fibers typically include a core surrounded by a transparent cladding material with a lower index of refraction.

Uses of Optical Fibers in various fields:

Communication:- 
  1. Used as a medium for telecommunication and computer networking because it is flexible and can be bundled as cables. 
  2. Advantageous for long-distance communications. 
  3. This fiber can carry many independent channels, each using a different wavelength of light. 
Sensors:- 
  1. Optical fiber is used to connect a non-fiber optic sensor to a measurement system. 
  2. These fibers are used as a sensor to measure strain, temperature, and pressure. 
Power transmission:
  1. It can be used to transmit power using a photovoltaic cell.
  2. It is especially useful for MRI machines, which produce strong magnetic fields.
Miscellaneous uses:
  1. Used in imaging optics.
  2. Light guides as medical and other applications where bright light needs.
Fibers that support many propagation paths are called Multi-mode optical fiber. Multimode optical fiber is way more powerful than the single- mode. A multi-mode cable has a much larger central core that allows a greater amount of light to travel through it at once. The core of a multi-mode cable is varied but usually, it is 50/125 or 62.5/125 microns in size. Increased core size means the light can refract at a greater rate.

Some of the Benefits of Fiber Optic cable:
  1. Optical fiber has a number of cores generally one core is used for transmission and another core is used for reception.
  2. Fiber optic cables have a much greater bandwidth than metal cables.
  3. Optical fiber can provide data transmission performance up to 10 Gbps. 
Specific Applications:
  1. Fibers are widely used in illumination application.
  2. They are used as a light guides in medical and other applications in some building.
  3. Fibers can use to route sunlight from the roof to another parts of the building.

Multimode Optical Fiber cables are extremely useful and are the primary thing of the fiber-optic networks. This type of cable is generally used for a short distance.

WPI’s Fiber optic cable is the only certified cable available in the market. It captures the low-level light events. The transmission percentage in this cable is so consistent and that it gives us the desired perfect result.

Fiber with a core diameter less than about ten times the wavelength cannot be modeled using geometric optics. It must be analyzed as an electromagnetic structure. The electromagnetic analysis may also be required to understand behaviors that occur when coherent light propagates in multi-mode fiber.  The fiber supports one or more confined modes by which light can propagate along the fiber. Fiber supporting only one mode is called single-mode -fiber. The behavior of multi-mode fiber can also be modeled using the wave equation.  If the fiber core is large it can support more than a few modes.

Cell Manipulation as a core interdisciplinary of biological science

Cell manipulation is a technique of genetic transfer; it helps in the prevention and treatment of different diseases. Cell manipulation...