Showing posts with label nano carbon. Show all posts
Showing posts with label nano carbon. Show all posts

Friday, July 31, 2009

Targeting Cancer with Nano Package

This is a nifty trick that finally finds a way to send toxins directly to and into the cancer cell. A very small liposome carries the toxin to the target and accommodates the attack.

This makes me recall some work that I was involved with twenty years ago when we discovered that extraordinarily small bits of carbon would form a shell of large organic molecules. This method should be applicable to a wide range of organic molecules. The trick was mainly to produce the form of the carbon we needed and it was derived from Korean War era work on artificial blood.

This makes the production of a range of organic nanoparticles feasible and opens the door to many serum based directed delivery systems

Presentation at AAPM Meeting on Nanoparticles That Package Cancer-killing Isotopes and Deliver Them Into Cancer Cells

Description

A group of researchers at Johns Hopkins University has designed nanoparticles that can carry cancer-treating radioisotopes through the body and deliver them selectively to tumors. Today in Anaheim, CA, they will report the latest results of their research, including studies in animal models, at the 51st meeting of the American Association of Physicists in Medicine (AAPM).

http://www.newswise.com/articles/view/554621/?sc=dwhn

Newswise — A group of researchers at Johns Hopkins University has designed nanoparticles that can carry cancer-treating radioisotopes through the body and deliver them selectively to tumors. Today in Anaheim, CA, they will report the latest results of their research, including studies in animal models, at the 51st meeting of the American Association of Physicists in Medicine (AAPM).

The nanoparticles are made with a commercially available product known as "liposomes" -- small chemical spheres made of fatty molecules that can package drugs and other chemicals. Liposomes are a powerful emerging tool in medicine because they can be designed to carry many different drugs and manipulated to control how long they stay in the bloodstream. One type of liposome, Doxil, is already approved by the U.S. Food and Drug Administration (FDA) for delivering Doxorubicin, a chemotherapeutic that is toxic to the heart.

The Hopkins scientists are using liposomes that have been modified with antibodies, a class of immune system proteins that recognize and bind to many different microscopic targets -- bacteria, viruses, other proteins, and human cells. Some antibodies specifically bind to cancer cells, and by attaching these cancer-specific antibodies to the liposomes, the scientists have created "immunoliposomes," which will wend their way through the bloodstream and seek out tumors inside the body. When they come into contact with their target cells, they deliver their payload into the cells.

"It's a promising approach to solving the problem of how to deliver more of a therapeutic to cancer cells," says George Sgouros, a radiology professor at Johns Hopkins who led the research.

Similar studies by other groups of researchers have already demonstrated how immunoliposomes could be packaged with tiny radioactive tracers used for imaging tumors. What Sgouros and his colleagues have done is figure out how to reproducibly package much more powerful radioisotopes, called alpha-particle emitters that have the ability to kill cancer cells without damaging nearby normal cells, and they have tested how effectively they can treat mice with a very aggressive type of metastatic breast cancer.
Early results show that they can pack a relatively large dose of radionuclides into the liposomes and substantially extend the life of treated mice.

"This treatment is much less toxic than chemotherapy because it is targeted to tumor cells rather than to all rapidly dividing cells " says Sgouros. "Nanoparticles designed to deliver these powerful isotopes have a great potential in cancer therapy, particularly for metastatic disease."

MORE INFORMATIONThe talk "Immunoliposomes for Targeted Radionuclide Therapy" is at 2:45 p.m. on Tuesday, July 28 in Room 303A. See:
http://www.aapm.org/meetings/09AM/PRAbs.asp?mid=42&aid=11894.

Tuesday, May 26, 2009

Lithium Battery Breakthrough

This news could not be better in terms of energy storage technologies. We now have a way to manufacture a composite using nano sized carbon fibers which is also non reactive and permits simple wicking of other substances. We can do this with molten sulphur but what is to stop us from doing the same with any and all other molten elements.

Recall that carbon and here we are working with elemental carbon has the highest melting point of any and all elements. I made use of that obscure fact to argue the existence of a carbon layer slip plane between the earth’s crust and the core. The same fact allows us to create full range of carbon based composites with the various elements.

Thus a woven carbon sheet might be dipped in molten titanium to form an advanced material superior to anything otherwise possible.

This and previously reported advances in lithium battery technology is speeding us toward the super battery that is a full order of magnitude superior to what is now possible.

It used to be that a bright young mind could tear apart a device and sort of figure out how it might work. That day is long past. Now we will be confronted with products whose critical structure will be invisible even under a microscope. Sort of like an UFO.

Major Breakthrough In Lithium Battery Technology

by Staff Writers
Ontario, Canada (SPX) May 21, 2009


http://www.energy-daily.com/reports/Major_Breakthrough_In_Lithium_Battery_Technology_999.html

An NSERC-funded lab at the University Of Waterloo has laid the groundwork for a lithium battery that can store and deliver more than three times the power of conventional lithium ion batteries.

The research team of professor Linda Nazar, graduate student David Xiulei Ji and postdoctoral fellow Kyu Tae Lee are one of the first to demonstrate robust electrochemical performance for a lithium-sulphur battery. The finding is reported in the on-line issue of Nature Materials.

The prospect of lithium-sulphur batteries has tantalized chemists for two decades, and not just because successfully combining the two chemists delivers much higher energy densities.

Sulphur is cheaper than many other materials currently used in lithium batteries. It has always showed great promise as the ideal partner for a safe, low cost, long lasting rechargeable battery, exactly the kind of battery needed for energy storage and transportation in a low carbon emission energy economy.

"The difficult challenge was always the cathode, the part of the battery that stores and releases electrons in the charge and recharge cycles," said Dr. Nazar. "To enable a reversible electrochemical reaction at high current rates, the electrically-active sulphur needs to remain in the most intimate contact with a conductor, such as carbon."

The Canadian research team leap-frogged the performance of other carbon-sulphur combinations by tackling the contact issue at the nanoscale level.

Although they say the same approach could be used with other materials, for their proof of concept study they chose a member of a highly structured and porous carbon family called mesoporous carbon. At the nanoscale level, this type of carbon has a very uniform pore diameter and pore volume.

Using a nanocasting method, the team assembled a structure of 6.5 nanometre thick carbon rods separated by empty three to four nanometre wide channels. Carbon microfibres spanning the empty channels kept the voids open and prevented collapse of the architecture.

Filling the tiny voids proved simple. Sulphur was heated and melted. Once in contact with the carbon, it was drawn or imbibed into the channels by capillary forces, where it solidified and shrunk to form sulphur nanofibres.

Scanning electron microscope sections revealed that all the spaces were uniformly filled with sulphur, exposing an enormous surface area of the active element to carbon and driving the exceptional test results of the new battery.

"This composite material can supply up to nearly 80 percent of the theoretical capacity of sulphur, which is three times the energy density of lithium transition metal oxide cathodes, at reasonable rates with good cycling stability," said Dr. Nazar.

What is more, the researchers say, the high capacity of the carbon to incorporate active material opens the door for similar "imbibed" composites that could have applications in many areas of materials science.

The research team continues to study the material to work out remaining challenges and refine the cathode's architecture and performance.

Dr. Nazar said a patent has been filed, and she is reviewing options for commercialization and practical applications.