SILICONE - A TRENDING BIOMATERIAL
R.PERUMAL SAMI,rperumalsamirdftijk@gmail.com,C.LALITHA LAKSHMI,lalithamufc@gmail.com, T.LAKSHMI,nandhini2013@gmail.com . ABSTRACT: Silicone polymers are of relatively recent invention and commercial production was started in the 1940's. Shortly thereafter it was found that glass surfaces treated with silicone fluid delayed the clotting of blood. By the mid-1950s medical applications of silicones had greatly increased and many studies of the biological properties of these materials were undertaken. Silicones are one of the most widely used and one of the most studied of all artificial materials for medical applications and no discussion of biomaterials is complete without their inclusion.
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This leads to a wide range of materials known as the silicones. This group of polymers, which have excellent biocompatibility, have been utilised to develop and manufacture a wide range of biomedical products. These range from simple tubing to complex implants, for example those used to replace diseased finger joints. The versatility of these materials has led to silicone products being employed in almost every medical speciality. Silicones, with their unique material properties, have found widespread application in healthcare. Properties attributed to silicone include biocompatibility and biodurability, hydrophobicity, low surface tension, and chemical and thermal stability. These properties were the basis for the initial use of silicone in the medical field. For example, their hydro-phobic (water-repellent) character caused silicones to be considered for blood coagulation prevention in the mid-1940s. Researchers from the Universities of Toronto and Manitoba obtained a methylchlorosilane from the Canadian General Electric Company and coated syringes, needles, and vials with the material. When rinsed with distilled water, the silane hydro-lyzed, forming a silicone coating on the
At the moment, the main objective for scientists and engineers is to develop surgery into a minimal invasive method and nanote...
Pit and fissure sealants are tooth coloured materials that are applied on the occlusal surfaces of the posterior teeth in deep grooves, pits and fissures. They protect the tooth from various bacterial plaques in these caries prone areas of the teeth. The sealants protect these areas by sealing of the entrance to bacteria which give rise to dental caries in susceptible individuals especially in children. Pit and fissure sealants are now commonly being used due to the increase in the awareness among public about dental caries prevention
Many hazards are associated with chemicals in this lab. Most of the chemicals used are irritating when they come in contact with your eyes, skin, or body tissues. Some chemicals are more dangerous, and can be corrosive to your body tissues. In one case, a chemical, when combined with any acids, can produce a toxic gas. In order to protect against these hazards, one must wear safety goggles throughout the entire lab as well as when cleaning up after the lab. Also, one should avoid contact with the chemicals and use extreme caution when handling each of the
There are three risk levels (low, medium and high) associated with sterile compounding. CSPs are assigned a risk level based on the probability of contaminating the preparation during compounding with microbial contaminants e.g. spores or endotoxins and chemical and physical contaminants e.g. skin particles from staff or broken glass. Once a CSP is classified, a licensed healthcare professional overseeing the sterile compounding can then decide upon the most suitable procedure and environmental quality of the facility which are necessary for preparing the CSP. The risk levels apply to the quality of the CSP d...
There are different method options a surgeon can use to a sterilizing surgical instrument and they’re streamed sterilization, Ethylene oxide, Hydrogen Peroxide Gas Plasma, Autoclaving, and Biological indicators. The first one is steam sterilization is very effective to kill off microorganism and also killing endospore by exposing the instrument to a high temperature of heat that caused under pressure causing stream that will automatically destroy any trace of microorganism. No living microorganism can survive at the temperature of 250 Fahrenheit that why important to place the appropriate temperature to kill off all microorganisms. The second method a surgeon can you for sterilization is called Ethylene oxide most commonly known as ETO is a neutral gas used for sterilizing the surgical instrument has the ability to kill off any living microorganism, however, its potential danger to patients and staff member because this gas has the potential to flammable result in an exposure . This type of glass must be kept in explosion proof chamber in a monitor environment, this gas is very harmful that 's why you must be trained in handling this ETO gas safety. There is a safer sterilization method to use beside Ethylene oxide, it’s called Low-Temperature Hydrogen Peroxide Plasma because it’s un-toxins and safe for patient and
In order to gain strong insight into the surface chemistry of silica we have perform a thorough literature search. Our goal is to identify the pioneer research performed on silica and silica supported catalyst. Particular interest lies in silica-water-cobalt and silica-alcohol-cobalt systems. This study is both on macro and micro level so that a complete theoretical base can be established. From this theoretical knowledge, key areas to look upon will be identified and a design of experiments will be established. The goal is to develop a both efficient and effective product (catalyst) using a novel methodology developed from past research.
Polyethylene (PE) is one of the most commonly used polymers which can be identified into two plastic identification codes: 2 for high-density polyethylene (HDPE) and 4 for low density polyethylene (LDPE). Polyethylene is sometimes called polyethene or polythene and is produced by an addition polymerisation reaction. The chemical formula for polyethylene is –(CH2-CH2)n– for both HDPE and LDPE. The formation of the polyethylene chain is created with the monomer ethylene (CH2=CH2).
First, let’s know about Conventional hydrogel contact lenses materials. They are polymers. The commonest of these is the first hydrogel material used for contact lens wear, poly (2-hydroxyethyl methacrylate) or polyHEMA (HEMA). PolyHEMA is cheap to produce, highly flexible, stable to changes in pH and temperature and has proved to be a very successful contact lens material. The main disadvantage of polyHEMA is that water has limited ability to dissolve and transport oxygen, with approximate oxygen permeability (Dk) of around 80 Dk units. In order to increase the Dk of a conventional hydrogel contact lens material, it is necessary to incorporate monomers that will bind more water into the polymer. These higher water content
Upon investigation, participants brought their own contact lens cases composed of a solution and a sample of their local tap water. Scientists also asked each person questions, regarding their contact lens history and method of disinfection. Upon laboratory experiments, scientists transferred the saline solution in each CLSC and tap water sample into centrifuge tubes. From the sides of the containers, they used cotton swabs to swipe samples of its contaminants (Üstüntürk, 2012). These samples were then fixed onto agar plates to test for fungal, amoebal, or bacterial contaminations, such as total aerobic mesophilic bacteria (TAMB), Gram negatives, and
How Blister Agents Changed Our Equipment We, as CBRN soldiers, can trace our corps roots back to World War I, where chemical agents were widely used by both the allied and German forces. One chemical used is called mustard gas (H). Mustard gas is a type of blister agent that causes large blisters (vesicles) on the skin, lungs and eyes of those exposed to it. According to Heller (1984), when mustard gas was introduced on the battlefield, soldiers were unaware that they were even exposed. Unlike other chemicals used at that time (Chlorine or Phosgene) the effects of mustard gas were not readily apparent.
The future for the total artificial heart with respect to using polyurethanes comes in the form of thermoplastic polyurethane (TPU), also known as polyurethane elastomers that have molecular structures similar to that of human proteins. TPUs have slower protein absorption (protein absorption is the beginning of the blood clotting process) this makes TPUs ideal candidates in the manufacturing of the total artificial heart because it provides more adhesive strength and mimics certain elements within the body. Hence, biomedical polyurethanes can lead the way to eliminate some acute health challenges that the total artificial heart currently faces. By virtue of their range of properties, polyurethanes and their new applications will continue to play an important role in the future of the total artificial heart.
“Implants and Prosthetics: Metal-on-Metal Hip Implants.” U S Food and Drug Administration Home Page, Center for Devices and Radiological Health, www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/ImplantsandProsthetics/MetalonMetalHipImplants/default.htm. Daines, Gary. “NASA's Journey to Mars.” NASA, NASA, 13 Feb. 2015, www.nasa.gov/content/nasas-journey-to-mars.
BACKGROUND Types of Silica Crystalline silica may be of several distinct types. Quartz, a form of silica and the most common mineral in the earth's crust, is associated with many types of rock. Other types of silica include cristobalite and tridymite. Potential for Exposure During Construction Concrete and masonry products contain silica, sand and rock containing silica. Since these products are primary materials for construction, construction workers may be easily exposed to respirable crystalline silica during activities such as the following: Chipping, hammering, and drilling of rock Crushing, loading, hauling, and dumping of rock   high dust concentrations.
There are numerous factors which can affect dimensions of subsequent casts on repetitive pouring. These include the process of polymerization (7), temperature (1), and material used to fabricate the replica or working cast (1). Although, PVS impression materials have demonstrated superior dimensional stability when compared with other elastomeric materials due to no releasing any by-products (8), it had been reported that the dimensional accuracy of a material is time dependent. A material may be highly dimensionally accurate soon after its initial polymerization but less accurate after the storage for a period of time (9). On the other hand, PVS impression materials have chosen as the impression material in many clinical situations because they possess excellent physical properties and handling characteristics
By convention, the field of healthcare research was entirely occupied by physicians and doctors. They were the ones who came up with new methods to treat diseases and get better results from diagnostic tests. Technology, on the other hand, was always looked at as a way to solve problems that we faced that didn’t pertain to the medical sector. It was employed to enhance the quality of life and make day to day work easier. But as technology progressed, so did the areas of application. The structural balancing techniques which were previously used to hold a building steady were now being used to develop near-perfect artificial joints and prosthetic limbs. Transparent polymers, developed to enhance robotic vision, were being suggested as a candidate for an artificial lens for the human eye. Before anyone could even understand what was happening, engineering had taken up the mantle to further medical technology to dizzying new heights.