johndevos

[johndevos]

As a chemist to be, your blog immediately catches the eye. In the future, alternative starting products to build polymers will be of crucial importance. Lignin seems like a promising product to replace petroleum, which is often used to retrieve the polymer starting products. Your blog is extremely interesting and informative. It got me thinking and I came upon some thoughts.

For one thing, lignin is supposed to be renewable. Does this mean that it could be retrieved from the application after usage and be reused to make another application. If so, I wonder if it would suffer the same problems that renewable polymers have today. Today, new polymer and recycled polymer are often put together to make a new ‘recycled’ product. However, recycling the polymers repeatedly is problematic as it leads to degradation and loss of physical properties. Will this be a problem when using lignin as a renewable building block of polymers. And if not, how is the use of lignin different to prevent this problem?

Furthermore, the rise of plastics was revolutionary because the products had good properties as well as a low production cost. An important contributing factor to this is the simple and cheap ‘click chemistry’ behind the polymer production. Click chemistry is a term used for chemical reactions which have few, simple steps and have high yields in every individual step. Lignin has to be broken down in order to use it as a building block for polymers. I wonder if this process is as easy to perform as the ‘click chemistry’ and if the needed catalyst to perform this reaction isn’t too expensive. Is the research in a stage in which a sustainable and cheap mass production method can be guaranteed as is the case today when using petroleum?

Generally, I certainly agree that lignin is a promising natural product that could reduce the use of beginning products derived from petroleum. I just think that the polymer industry will be reluctant to its usage, until they are guaranteed a cost efficient and durable production method. I really enjoyed reading your blog as it covers a topic that few people think about, but will be very important in the future.

Lignin: the chemical compound that will reshape the future of petroleum

Everybody knows that the world and more specifically the chemical industry, runs on petroleum. We can’t live without it, it is literally everywhere: in your house, in your car, even the plastic bottle you are drinking from is made from petroleum. For the past hundred years men exploited this so called black gold for their own advantage, but recently it became clear that this exploitation must stop. The reason is quite clear: global warming, of which petroleum use is a significant cause. You might ask yourself: Does this mean that we can’t use products derived from petroleum anymore? The answer is neither yes nor no: the use of petroleum must stop, but the products derived from it can be made from a renewable compound called lignin.

So, what is lignin? Lignin is a substance responsible for the firmness and strength of plants and is present in almost all plants and trees. As you might have guessed, this lignin needs to be extracted from the plant before it can be used. This does not pose a problem as extracted lignin is a by-product of the paper industry and 98% of it just gets burned for energy production. This by-product stream of the paper industry forms the ideal first step for the use of lignin as a replacement for petroleum  

If you are thinking that this so called substance ‘lignin’ must have a complex and big structure, you are right. This complex structure can be described as a big Lego wall: it isn’t ugly, but it would be much nicer if you could break it down and build something else. This is exactly what must happen with lignin before it can be used as a substitute for petroleum. The easiest and most promising way to do this is by using a catalyst, a special compound that makes the ‘breaking down’ part less energy demanding.

Once this catalyst has been used, the product consists of similar molecules as the molecules found in natural occurring petroleum. This product is a sort of renewable and natural form of petroleum and can be used for the same uses as petroleum. This way you can still enjoy your plastic bottles without making as big of an impact on the environment, but remember: using reusable bottles is even better!

Sources:

https://pubs.rsc.org/en/content/articlelanding/2018/cs/c7cs00566k#!divAbstract

https://www.degruyter.com/view/journals/cse/7/1/article-p1.xml

[johndevos]

Llamas could be the cure to Alzheimer’s disease

The chances of you getting dementia are 1 out of 5. This is an estimation published by the World Health Organization based on the wide distribution of diseases targeting the central nervous center, like Alzheimer’s disease. This illness is very difficult to treat. That’s a result of the so-called blood-brain barrier (BBB). This is a selective border separating the brain from the blood circulation, making it difficult to transfer drugs from the blood to the brain and fight the disease. Luckily science never sleeps and a recent study using nanobodies as a diagnostic and therapeutic tool has had  very promising results.

But what are nanobodies?

Every organism makes antibodies to fight diseases. The production of these antibodies is triggered when an unknown substance enters the body. Antibodies have a general structure, which is the same for many species. However, next to the conventional antibodies, camelids, like alpacas and llamas, also have a special kind of antibodies. These are much smaller than the normal ones and are conveniently called nanobodies.

Why use nanobodies to diagnose and treat Alzheimer’s?

After chemical modification, nanobodies are able to bind to the specific plaques and tangles, which cause the disease. Plaques grow when certain proteins are not properly degenerated. They are accumulations of these proteins. Tangles are entanglements of different proteins.  The nanobodies can specifically recognize these targets and bind to them. By binding a dye to the nanobody prior to injection, it is later possible to visualize the plaques and tangles. This way it becomes possible to diagnose these precursors of the disease. The same way, drugs could be bound to the nanobody, making it possible to cross the BBB.

What does this mean for the future?

Right now, the research is still in the early stages. There haven’t been  human trials yet. But the same procedure used during the tests with mice  could most likely be applied to the human brain as well. This creates an opportunity for the future treatment of these diseases. Firstly, it will be possible to diagnose the disease early on. Secondly, it’s possible to bind specific medicines to the nanobodies. This way, the nanobodies can deliver the medicines across the BBB, so they can target the plaques and tangles. So, it seems that the solution to a large problem could be very small.

reference:

T. Li, M. Vandesquille, F. Koukouli, C. Dudeffant, I. Youssef, P. Lenormand, C. Ganneau, U. Maskos, C. Czech, F. Grueninger, C. Duyckaerts, M. Dhenain, S. Bay, B. Delatour and P. Lafaye, J. Control. Release, 2016, 243, 1