Tuesday, 26 June 2012

How to Make Vaccines with a longer Shelf Life Faster for the Next Bird Flu Outbreak???

Like milk vaccines are a colloid.  What the hell is a colloid?  A colloidal system consists of two separate phases: a dispersed phase (or internal phase like fat in milk) and a continuous phase (or dispersion medium like water) in which the colloid is dispersed. WIth many colloids the surface tension is damn important.  When the phases seperate in milk as in non-homogenized natural milk, the fat droplets in the milk can be attacked easier by enzymes or be degraded by physical factors (heat).  However, when the homogenization takes place these fat droplets are dispersed within the milk and pasteurization can destroy the enzymes allowing a longer shelf life. A new technique called ultrahomogenization creates a colloid suspension of smaller more uniform droplets by increasing the amount of pressure in the homogenization process by seven times.

How does this relate to vaccines?  Like milk vaccines are also a colloid.  They are a suspension made from some microbe.  It is often made from weakened or killed forms of the microbe, its toxins or one of its surface proteins. These agents can stimulate some the immune response in the T-cells in the body after getting the vaccination.  By stimulating the memory T-cells you will be hopefully resistant to the actual active microbe when it is present.

One problem persists with vaccines as it does with milk.  Since vaccines discovery by Edward Jenner in 1770 there has been a difficult thing of making, storing and transporting the vaccines.  Since vaccines are a colloid an subject to physical and enzymatic degradation as other colloids they can expire (like milk).  Vaccine shortage is always a problem and a bigger problem in places other than North America.  The avian flu (see picture below) spread quickly but was not as widespread in places of people that got flu vaccines.  So how do make a vaccine last longer?  You change the surface tension of the vaccine emulsion.

One army researcher found that by changing the composition of an emulsion from a simple oil and water emulsion the imulsion is only good for a couple of months because it is not thermodynamically stable.  However, when you change the composition to an isotropic liquid of oil, water, glycerol, and surface tension lowering surfactants span 80 and tween 60 along with the proteins used in the vaccine can stay on the shelf for six months.  

U.S. Army Major Jean M. Muderhwa found this solution recently.  The higher amount of molecules found in most emulsion, heightened the surface tension results in components repelling each other until the composition degrades and fails.  The army helps to stockpile the vaccines in case of emergency.  If all goes well it will help them stockpile the vaccines for longer time for larger emergencies flu virus

So how can one make the process of measuring surface tension faster?  Nearly an infinite number of surfactants can be added to the emulsion to lower the surface tension.  Several different devices could be used for measuring surface tension but only one has high throughput capabilities.  Kibron's Delta-8 could be a reliable device to test the surface tension of different vaccine emulsions to help prolong their shelf life.  The best part is as the video shows.  It's damn fast!

Thursday, 21 June 2012

Powering a Boat using the Marangoni Effect

Two things Finns love.  Alcohol and boating.  Combining them as Robin Ras did at Aalto University makes absolute magic.  This scientist made a boat out of a substance called Aerogel run for nearly an hour.  Watch the video then see how it works.

This will not work for a freighter, or even a canoe unfortunately.  The gel is still really expensive to produce and not really durable enough.  It does make scientists think about boat propulsion and may be used to reduce the drag on large ships.  Maybe in the future we will go further and have interesting crafts without using any fuel but propelled only by the physical chemical properties of water and a sip of your beer (too bad alcohol in Finland has such a high tax rate!)

Watch the video:

How does this work?

The craft doesn't have an equally tiny motor pushing it through the water. Instead, as the ethanol on the rear of the craft vaporizes and passes through the aerogel's nanocellulose membrane, it lowers the surface tension of the water around the boat.  When the surface tension is lowered around the boat less friction is working against it.  But as the front of the boat passes and the surface tension of the water behind it increases again, it tends to naturally push it along.  In summary the boat can travel 74 meters for 54 minutes on only 25 microliters of ethanol.  This was reported in New Scientist.

Man Mimicking Nature

Again mankind is only mimicking what nature already does really well.  Water striders excrete surfactants to help them move in water better.

Sunday, 17 June 2012

Making a Surface Tensiometer Out of Lego

I picked up Wired to day to see the picture below. I did not look at the article but I thought that looks like a Du Nuöy ring a little. Well the researcher Daniel Strange who was working on his Masters degree at Cambridge came up with a solution for his project (nothing to do with surface tension) using lego. His project uses robots to mimic the composition of bones. To do this Daniel now doing his PhD in biomedical engineering under the supervision of Michelle Oyen built a robot out of legos. If a 12 year old kid could do it so can a PhD researcher, right?

The resulting crane like structure is clumsy but gets the job done. A similar device would have cost thousands of euros. Could one make a tensiometer out of Lego? It would be not as elegant, accurate nor as portable as a Kibron device but it could probably be done. I should try...