Contact Us
Sign In / Sign Up for FREE
Go to advanced search...

Gas-filled Liposomes - Essay Example

Comments (0) Cite this document
Liposomes have been used for many years as delivery vehicles for pharmaceuticals due to their intrinsic ability to fuse with the cellular membrane to deliver a therapeutic dose directly to the cell. More recently these lipid containing vesicles have demonstrated expanded use as gas-filled membrane-bound vesicles that can act as pressure points for use in magnetic resonance imaging (MRI) studies (Vangala et al, 2007)…
Download full paperFile format: .doc, available for editing
GRAB THE BEST PAPER96.3% of users find it useful
Gas-filled Liposomes
Read TextPreview

Extract of sample "Gas-filled Liposomes"

Download file to see previous pages In medicine, MRI is an invaluable tool for soft tissue assessment as it analyses the absorption and transmission of high frequency radio waves absorbed by water in high magnetic fields to derive cross-sectional images of soft tissue (Alexander et al, 1996; Maresca et al, 1998). The use of GFLs as components of tracer materials may enhance the use of this technology in medical diagnostics (Klibanov, 1999).
A recently developed method of GFL preparation (Vangala et al, 2007) involves the homogenization of 1,2-dipalmitoyl-sn-glycero3-phosphorocholine (DPPC) or 1,2-distearoyl-sn-glycero-3-phosphorocholine DSPC in aqueous medium below their transition temperatures to effect a stable GFL formation. Biophysical assessment indicated that the initial vesicle size was 10microm, which increased to approximately 12 microm for DPPC and 23 microm for DSPC containing vesicles in 7 days at 25C. The addition of cholesterol 1: 0.5 or 1:1 to the DPPC lipid homogenate produced significant increases in vesicle size as well as enhanced stability compared to DPPC alone (Liu et al, 2000). Surface charge induction was implemented by the addition of stearylamine at a molar ratio of 0.125 or 0.25. The surfactant did not appear to be incorporated into the bilayer. Microscopic analyses demonstrated that spherical structures ranging from 1-8 microm were produced by this method. When used as cardiographic contrast agents in cardiac assessment in experimental animals, GFL performed with greater sensitivity than aqueous liposomes (Mohammed et al, 2004; Unger et al, 1992, 1993).
2-Aim and Objective
The objective of this research is to prepare Gas-filled liposomes (GFL) and to characterize their biophysical properties. The goal is to prepare liposomes that are gas-filled (air) using experimental lipid components and to assess their stability and biophysical properties. This assessment may facilitate the use of GFL for both medicinal purposes in MRI and in environmental studies such as novel methods for oil recovery.
Sigma-Aldrich (Poole, Dorset, UK)
1,2-dimysteroyl-sn-glycero-3-phosphorocholine DMPC(C14)
1,2-dipalmitoyl-sn-glycero-3-phosphorocholone DPPC (C16)
1,2-distearoyl-sn-glycero-3-phosphorylcholine DSPC (C18)
methyl cellulose
phosphate buffered saline tablets
Lipid Products (Nutfield, Surrey, UK)
egg-phosphatidylcholine (PC)
double-distilled water
Gas-filled liposome preparation:
GFL will be prepared using a modified method first developed by Unger (1999). This method involves the following steps:
1. 50 mg of DSPC or other lipid added to 5ml of doubly-distilled water in a 50ml beaker to hydrate the lipid. Cholesterol or stearylamine should be added if these components are to be included in the vesicle preparation.
2. Mixture is homogenized for 4 minutes below the phase transition temperature of the lipid using a high speed homogeniser (Ultra -Turrax T8).
3. A gas (air) filled lipid layer will form above the aqueous layer following homogenization: this constitutes the GFL fraction.
4. Varying GFL concentrations will be prepared by mixing varying volumes ...Download file to see next pagesRead More
Cite this document
  • APA
  • MLA
(“Gas-filled Liposomes Essay Example | Topics and Well Written Essays - 750 words”, n.d.)
Retrieved from
(Gas-Filled Liposomes Essay Example | Topics and Well Written Essays - 750 Words)
“Gas-Filled Liposomes Essay Example | Topics and Well Written Essays - 750 Words”, n.d.
  • Cited: 0 times
Comments (0)
Click to create a comment or rate a document

CHECK THESE SAMPLES OF Gas-filled Liposomes

E85 gas vs. regular gas

... Sedans Crown Victoria, Mercury Grand Marquis, Lincoln Town Car, Escape Hybrid E85) (Byrge & Kliesen, 2008, p. 5). Global interest in alternative (renewable) fuels was imposed, first of all, by different national environmental programs. It is known that the use of renewable fuels in a given region can reduce: • Greenhouse gas emission - by 14 – 19% (9, 5 million tons of СО2 in 2008); • Consumption of petroleum products - by 73 - 75 %; • Use of fossil fuels - by 13 - 35 %. In addition to the environmental aspect, use of ethanol - gasoline mixes (E85) has the following advantages compared to regular gasoline: higher octane number, which means lower wear and increased life of a car engine; reduced vehicles’ service charges; lower cost of E85...
3 Pages(750 words)Essay

Hildegard's Spirit-Filled, Visionary Music

...?Brescia Hildegard’s Spirit-Filled, Visionary Music Nicole McDaniels Nicole McDaniels February 4, 212 Hildegard’s Spirit-Filled, Visionary Music Some people live such extraordinary lives that their death doesn’t particularly slow the spread of their influence at all. Hildegard Von Bingen was such a person, and music was central to her experience and to her identity. In fact, she referred to herself as a tone from the tuba of God (Phillips 59). This paper aims to provide some insight into her life, and to discuss the impact her music has had on both secular and sacred music that followed. She was born in Bermersheim, near Alzey, in the summer of 1098, to a noble family. She had her first visionary experience before the age of five...
6 Pages(1500 words)Term Paper

Greenhouse Gas

...? Unit 6 U06a1 There are certain significant aspects that impose extensive impact especially upon the environment by a greater level. With this concern, this part of the project would broadly comprise analyzing the perceptions like Greenhouse Gas, CFC, Air Pollution (Carbon Monoxide), Water Conservation and Land Pollution. The following discussion would ultimately reveal that the changes in the aforesaid aspects are quite important. Greenhouse Gas- This is generally formed due to the effect of infrared radiation. It is also formed by way of absorbing infrared radiation i.e. carbondioxide. This gas largely contributes to the occurrence of greenhouse effect in terms of generating large amount of heat in the earth surface. Relevant measures...
4 Pages(1000 words)Research Paper

Australian Gas

... three years has remained relatively stable as well. In February 2003 the stock was trading at about 10.00 per share and had earnings of 73 cents that gave it a P/E of approximately 14. In February 2004 the stock was trading at just over 11.00 per share and had earnings of 79 which kept the P/E very close to 14 and in February of 2005 the stock was trading at approximately 13.25 per share and had earnings of 84 cents. This caused the P/E to jump slightly to approximately 16 which was still well within the average P/E of other gas and electric companies. RISKS There are a myriad of risk factors for this company, including (but not limited to): rates being set by the regulatory board that are not in line with company...
3 Pages(750 words)Essay

Gas Chromatography

...History of Gas Chromatography Chromatography is a Greek word which originated from the word chroma standing for the word color. It is a scientific technique that refers to separating mixtures. It comprises of two main different phases; mobile and the stationary phase. Gas chromatography is identified by the fact that the carrier gas is formed in the mobile phase. The carrier gases can be helium which is an inert gas and nitrogen which is an un-reactive gas. The stationary phase is characterized by a column whose layer of liquid is microscopic or polymer found inside a metal tube or glass. Gas chromatograph is an instrument used to perform gas chromatography. It is also referred to as gas separator or aerograph. Gas chromatography...
7 Pages(1750 words)Term Paper

Gas Cell

Configured for gas sampling, the cell incorporates 2 valves, an inlet and an outlet, that enable flowing gas samples through the cell. In its solid and liquid vaporization configuration, the cell has an outlet needle valve from which a vacuum can be pulled and two (2) sample inlets.
One inlet is a needle septa injection port on the top of the cell which is similar to the type used in gas chromatography. There is a second inlet in the form of a side port for inserting solid samples, which also doubles as the thermocouple port. Using the side port eliminates the need to recheck vacuum seals whenever the cell is opened to insert solid samples. The 250w heating jacket extends over the end of the cell so that both the cell body an...
3 Pages(750 words)Essay

Natural gas

...Natural gas What is natural Gas? Natural gas, also called marsh or swamp gas in older texts and more recently known as landfill gas is a viable, abundant, low cost, low emission naturally occurring gaseous fossil fuel found in oil fields, natural gas fields and coal beds and used as an energy source in numerous economic sectors across the world. Technically, it is a mixture of various alkanes’ hydrocarbons primarily of saturated light paraffins such as methane and ethane, both of which are gaseous under atmospheric conditions. The mixture also may contain other heaver hydrocarbons, such as propane, butane, pentane, and hexane and few other gases such as nitrogen, carbon monoxide carbon dioxide etc. In natural gas reservoirs beneath...
5 Pages(1250 words)Essay

Natural gas

...Natural Gas: A Good Source of Energy Natural gas is one of the most important sources of energy. There are a variety of opinions surrounding naturalgas. Natural gas is a fossil fuel just like coal and oil. It forms much below the earth’s surface. Natural gas primarily constitutes methane which is the lightest hydrocarbon. Natural gas neither has odor nor color and yields a lot of energy when burned, which makes it a good source of energy for all sorts of domestic and industrial purposes. However, natural gas is not renewable since it is a fossil fuel. The International Energy Agency (IEA) published a World Energy Outlook report in the year 2011 in which, the production of natural gas was estimated to increase by 50 per cent over the next...
4 Pages(1000 words)Essay

Gas law

... Gas laws Objective Investigate the relationship between pressure, temperature, volume, and the amount of gas occupying an enclosed room. This experiment consists of three parts. In part one, the relationship between pressure and volume will be measured. In part two, the relationship between pressure and the amount of gas present in the chamber will be determined. Part three will illustrate the relationship between pressure and temperature. The results of these measurements will be used to derive the Ideal Gas Law. Data Temperature, K Volume, L Vapor Pressure, atm PH2O PH2O/Ptotal Vair, L 339.05 0.01 26.167 0.963190636 107.731009 332.45 0.009 19.028 0.950069902 145.266044 327.45 0.0085 15.012 0.93754684 181.358265 324.95 0.0082 13.623...
1 Pages(250 words)Essay

Need questions filled out for me

...Literature Assignment Is Confucius stressing on the importance of actual ritual or the inner attitude (P.1334) No, Confucius fails to address on the importance of actual ritual or the inner attitude by multiple justifications. First and foremost, Mozi one of the Confucious critic justify the failure by stating that Confucious is a helplessly outdated or old-fashion that stress only on the importance of rituals only when there are benefits attributed to it. For example, in the presence of a good meal obtained from sacrificial occasions Confucius may intend to stress on actual ritual or inner attitude (P. 1334, paragraph 2 line 8-16). In addition, the Chinese government regards Confucius as evil and blames it for the loss... Assignment Is...
1 Pages(250 words)Assignment

History of Gas Prices and their Effect on the Economy

The relation of inflation within a society with the ever-changing oil and gas prices is pretty much significant and one must understand that there is a strong bond present between the two. This strong linkage allows for prices to shoot up whenever there is a sudden upward trend experienced in the oil and gas prices and whenever the gold rates have increased on the global front. With so much at stake and economies coming to a standstill with the uprising trend in the oil and gas prices on a global level, one can only expect problems coming to the fore of the common man and woman present on the street. The worst possible explanation given by experts in the field of oil and gas prices’ regimes is that these are done to benefit...
9 Pages(2250 words)Coursework

Provisions for Gas, Electricity, and Water Markets

...Gas, Electri and Water Competition Thirty years ago, the consensus was that network utilities, such as gas, electri and water were essentially natural monopolies where competition was neither feasible nor desirable therefore they were regarded as public sector. However the consensus has changed.Competition is generally seen to be possible and desirable in such utilities therefore regulators now have all primary duties to promote competition. From a regulator`s point of view, it is crucial to have a clear view of what a competitive market is and what can be done, in the real world, to establish the conditions that will allow such a market to emerge. Traditional vs. New Approach The traditional regulation relied on static concept...
9 Pages(2250 words)Report

The Bhopal Gas Disaster

In the incident, a toxic gas called methyl isocyanate (MIC) weighing around 42 tonnes was released into a city with a population estimated at 500,000 people. The incident was devastating: the immediate death toll was 2,259 people. Generally, it is estimated that 8,000 people died in the first two weeks and more than 8,000 died later from gas-related complications. It is believed this is the worst industrial incident of the recent past.
The Union Carbide India was a company that produced carbonyl pesticide, which is an intermediate product of methyl isocyanate. The methyl isocyanate is a toxic material but cheaper compared to other raw materials that could have been used. However, the chemical involved in this incident was a c...
7 Pages(1750 words)Case Study

The Effects of Financial Crisis on Supplier Selection Criteria of the Oil and Gas Industry Equipment Market

It is a difficult task to find those vendors who not only have the adequate quality and quantity of the needed raw materials but who also have an attitude of efficiency and display commitment to customer service (Sonmat, 2006). Further, organizations also strive to locate and select vendors who can be depended upon for long term relationship.

The number of factors or attributes desired from the vendor is vast, and different organizations and different industries place different importance on the attributes (Sonmat, 2006). Some of the vendor attributes may gain importance owing to the nature of the industry, for example, in the case of consumer perishables suppliers, like fresh vegetables or fruits, the buying firm would...
20 Pages(5000 words)Literature review

Natural Gas Production in Eastern Kentucky Had a Negative Impact on Water Quality

...Has the recent surge in oil and natural gas production in eastern Kentucky had a negative impact on water quality/quantity in the area? The increased energy needs of countries worldwide has led to the expansion of activities that aim to address the above needs, either in the short or the long term. Usually, the relevant initiatives are not appropriately monitored leading to severe environmental damages. The problem is acute both in the developed and the developing countries. The oil and gas production activities developed in eastern Kentucky are indicative cases of such type; efforts have been made by the local authorities to minimize the effects of these activities on the region’s natural environment, however, this target has not been...
8 Pages(2000 words)Essay

Human Biological Systems, Gas Exchange & Transport

...Gas Exchange and Transport Gas Exchange and Transport TAQ Explain the structure of the respiratory system. Respiratory System Component Structure Function(s) 1. Respiratory Controller a) Cerebral Cortex b) Brainstem: “Medulla Oblongata” and “Pons” are two major structures that provide respiratory control. (Speck et al, 1993, p.39, 43). Each of them contains two respiratory centers. There are total four respiratory centers in the brainstem; Inspiratory center, Expiratory center, Pneumotaxic center and Apneustic center. Cerebral cortex provides behavioral control, whereas, brainstem provides an autonomic control for respiration. Overall, this CNS control determines the depth and frequency of the respiration. (Schwartzstein & Parker, 2006, p...
8 Pages(2000 words)Assignment

Oil and Gas Exploration Prudent Development Through Environmental Awareness

...U.S. Oil and Gas Exploration Prudent Development U.S. Oiland Gas Exploration Prudent Development Introduction Awareness regarding the significance of environmental issues is currently central to the thoughts of the oil and gas industry, as well as regulators. The integration of the environment and development is the theme of many stakeholder meetings between environmental agencies and oil and gas industries. International bodies are also part of this conversation; for instance, the United Nations Environmental Program headquartered in Kenya held a conference in Rio in 1992. Part of the declaration principles pointed to the fact that sustainable development is solely dependent on environmental protection. Such declarations aim...
7 Pages(1750 words)Literature review

Gas Release Evacuation Plan

...Gas Release Evacuation Plan In most industrial and transportation accidents, hazardous gases may often leak into the environment in such quantities or proximity to individuals that necessitates evacuation of the employees to safer grounds. Although there are a number of universal procedures that must always be followed, the type of gas release evacuation plan usually depend the size of the workforce and availability of onsite resources. This report proposes an evacuation plan that should be used in the event of a gas release. Gas Release Evacuation Plan Introduction The effectiveness of a gas release plan depends on the coordination of the occupants of the affected area. Generally, both the employees and the employers within...
9 Pages(2250 words)Term Paper

Sources of Air Quality Pollutants and Greenhouse Gas Emissions

...A Case Study of Sources of Air Quality Pollutants, Greenhouse Gas Emissions and Associated Action Plans at Bootle Docks Throughout the United Kingdom a standard of eventual compliance with other nations of the European Union in a framework of environmental modernization with respect to air quality and pollution controls are being implemented. The modernization strategy is occurring across the continent in order to avert environmental consequences with negative repercussions for both human health, and the climate at large. Across Europe, an initiative is taking place to begin a gradual shift towards emissions standards dependent upon a reorganization of current patterns of urbanization (Ekins & Lees, 2008), as well as technological...
17 Pages(4250 words)Case Study

Sustainability in Gazprom Gas Production

...Sustainability in Gazprom Gas Production Executive Summary The energy sector has attracted a lot of controversy as a major source ofgreenhouse gases that result in global warming. Gazprom is a leading generator of gas in Russia and has been extensively involved in sustainability measures to ensure that the company produces low-carbon gas. The EU, as the largest market for natural gas is highly liberalized thereby setting a strategic market for Gazprom to open its market to global gas users. By 2050, Gazprom seeks to be the leading producer of natural gas and importer in the EU region. This is following the current market trends which show that there is an increasingly high number of gas consumption the globe that is likely to increase...
8 Pages(2000 words)Assignment
sponsored ads
We use cookies to create the best experience for you. Keep on browsing if you are OK with that, or find out how to manage cookies.

Let us find you another Essay on topic Gas-filled Liposomes for FREE!

Contact Us