Author Archives: tarek el sayed

Are we a step closer to synthesizing people ?

Posted on November 25, 2017 | 1 comment

Having a trouble making friends? How about building a friend?! New research at the University of Harvard by Pang Yui has brought us one step closer to synthesizing living beings.  Synthesizing animals and people seems like an impossible task but it’s definitely more attainable now thanks to this fascinating research. You might be surprised what this new finding has to offer.

Many different types of cells make up the human body. DNA strands, which are the building block of genetic material in the body form the different types of cells.  In our body,  base nucleotides known as the A, C, G, T, which have the potential to fold into 3D structures make up DNA. Hydrogen bonding between the base pairs of nucleotides determines base pairing.  For example, As and Ts and Cs and Gs bind to each other. In order for the cell to grow, develop, and repair itself, many changes occur in the DNA to allow cells to replicate. 

Related image

Figure 1. A photo demonstrating the base pairing in DNA structure

For many years, people understood the complex machinery behind DNA replication. Can we synthetically make DNA? Scientists have previously tried to make copies of DNA in test tubes. However, this technique known as PCR is limited to amplifying DNA segments. It might be a Nobel-prize winner technique but definitely, we cannot rely on PCR to build large strands of DNA.  Pang Yui, a researcher at the University of Harvard developed a new method that allows pre-designed sequences of DNA to autonomously grow. The Primer Exchange Reaction (PER) is a method that offers autonomous and programmable features that have very diverse applications in the field of synthetic biology. Some of these applications involve the engineering of molecular devices, that are capable of synthesizing large DNA nanostructures.  These nanostructures are able to sense environmental signal in the cell which allows them to grow autonomously and carry different functions. This method represents advances in the field of molecular robotics since pre-designed DNA molecules can be programmed to self-assemble in 3D structures, that are able to carry certain functions and tasks. 

Autonomously growing synthetic DNA strands

Figure2. The method of Primer Exchange reaction which gives rise to autonomously grown DNA that is able to carry different tasks. Image credit: Wyss Institute at the University of Harvard 

The method of PER needs very basic requirements. Firstly, you need “an engine” in the form of Single-stranded DNA that has the potential to partially pair with itself. Secondly, you need a primer that is complementary to the piece of single-stranded DNA. Through a series of elongation and displacement reactions, the primer is able to copy the sequence of DNA in-situ.Once these reactions are over, the DNA is expelled and is allowed to be recycled in this process to make large strands of DNA.  

This method represents the future of technology. If we can program DNA to do specific tasks and functions, we can definitely synthesize people. All you need is making proteins which are crucial in many cellular processes. If this new research is able to synthesize proteins, we are one step closer to synthesizing animals and people who can keep our company.

By: Tarek El Sayed

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Posted in Admin, Synthesis

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Ferrocene: A powerful organometallic compound that has various medicinal applications

Posted on October 30, 2017 | 1 comment

Research in medicinal chemistry has been booming in the last few years due to important discoveries made by fellow scientists. Ferrocene which is one of the most famous organometallic structures discovered in the early 1900’s can open many routes in cancer research. The discovery of the first sandwich complex opened a new area of research and since then many similar structures have been synthesized. Wilkinson and Fischer received a Nobel prize in chemistry for their remarkable work in developing sandwich structures using transition metals. A sandwich complex is defined as a metal center connected to aromatic rings. When ferrocene was discovered, its medicinal applications were not known. Recently, Ferrocene and its derivatives have found their way in medicinal chemistry as anti-cancer and HIV agents.

Figure 1: The structure of Ferrocene consisting of an iron metal centered around two aromatic rings. The name sandwich complex comes from the fact that the metal is sandwiched between two molecules.

In order to understand the mechanism behind ferrocene acting as an anti-cancer agent, basic understanding of anti-cancer agents is required.  There is an enzyme in the body known as Topoisomerase that keeps the topology of DNA by unwinding the DNA for replication. Tumour cells increase the activity of topoisomerase; thus anti-tumor drugs act by lowering the activity of topoisomerase. Ferrocenium ions get reduced in the cell generating a hydroxyl radical. These radicals are responsible for biological damage in cancer cells. The ferrocenium species target specifically a protein complex that binds to a specific region of DNA. The above mechanism helps in inhibiting the activity of cancerous cells. Damaging the tumor cells responsible for increasing topoisomerase activity helps regulate the activity of DNA.

Figure 2: A detailed mechanism of how Ferrocene and its derivatives get reduced in the cell causing cancerous cells to die

Ferrocene derivatives are also used in regulating HIV virus which is responsible for AIDS. According to recent studies, 75,500 Canadians were living with HIV by the end 2014. The number of Canadians affected by HIV has increased dramatically in the last few years and many scientists are trying to find therapeutic agents that can target HIV. The same enzyme mentioned above known as Topoisomerase is also involved in HIV. Researchers have shown that topoisomerase is involved in HIV replication cycle. Viruses have the tendency to use the cell machinery to replicate and survive inside the body. Ferrocene derivatives are very effective in inhibiting the activity of topoisomerase involved in HIV replication. Some drugs containing ferrocene gave promising results as Anti-HIV agents. These compounds are thought to inhibit the synthesis of viral DNA.

Figure 3: Some common Ferrocene compounds and their use in medicinal chemistry

In Conclusion, organometallic compounds have unique properties that allow them to have wide applications in medicinal chemistry. Attaching ferrocene and its derivatives to biological drugs will serve in increasing the efficiency of drugs. The possibility of using ferrocene in medicinal applications are endless. Hopefully, this powerful class of compounds could find its way to market shelves soon.

By: Tarek El Sayed

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Posted in Manufacturing, Synthesis

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Did Martian gave hope to young explorers ?

Posted on October 2, 2017 | 1 comment

Whenever a new science fiction movie comes out, there’s often a lot of talk about how “accurate” it is, and this is usually in reference to the science: Can dinosaur DNA really come from a preserved mosquito? Can an asteroid really be deflected with a nuclear bomb?Usually, the scientific content of these movies is inaccurate, as movie directors try to engage in fantasy by having monsters and magic.  If it doesn’t involve post-apocalyptic scenes of zombies invading the Earth, it is not appetizing for the over-demanding audience.  With this in mind, “The Martian” might be one of the most accurate movies in terms of scientific content. However, it still exaggerates many aspects related to agriculture and fails to mention the reality behind trying to grow plants on Mars.

Farming on Mars

In the movie, after becoming stranded on the surface of Mars, Watney resorts to using a combination of his excrement, water, and Martian soil to grow potatoes. But is this realistic? Could the Martian soil be of any use? Isn’t it sterile and dead?

In terms of basic mineral content and chemical content, yes, it would be possible to grow plants in the Martian Soil. In fact, scientists conducted research on the chemical composition of rocks from Mars. They found that mars contained many bio-elements such as Potassium, Calcium, and Iron. Scientists claim that the rocky material on Mars is fertile and has the potential to yield extremely productive soils.

Well, kudos to the director for getting these facts right but Hang on! Is using human excrements even safe? No, it is not. Many studies show that using excrements could result in major health problems. It could spread disease and have a serious impact on human health.

 Water Availability  

Matt Damon’s character took hydrazine from the rocket and dissociated it into nitrogen and hydrogen. He then mixed the hydrogen with oxygen to make water. This process is doable if I was an expert on how to extract fuel and knew basic chemistry. It could certainly work but if I was stranded on Mars, I will just make water out of the soil. Water is available in its natural state on Mars as ice, permafrost or soaked into the soil. Martian soil is about 5% water. by weight, at low latitude and up to 60% water near the poles. Martians are not going to get their water by importing hydrazine and burning it with precious cabin oxygen, they are going to find it in the soil!

The Martian was a great movie in terms of depicting scientific content. It succeeded in inspiring young people to consider the possibility of conquering space. However, before you pack your bags and move to Mars, you must know that surviving on Mars could be a struggle. Even though the elements of life might be available on Mars, trying to sustain human life will be a challenge.

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