ChemSemBlog

Chemistry seminar on March 4th, 2010 was presented by Joseph Heinzelmann. He is a product manager for Dendritic Nanotechnologies Inc. I would describe this seminar as a description of the applications of new polymers called dendrimers, and new insight into the use of a chemistry degree. The presentation consisted of two parts. The first described dendrimers.  The second part of the presentation focused on the use of a chemistry or biochemistry degree.

Nomenclature or dendrimers begins with branching then the surface groups. Dendrimers were found to be 1-10nm in diameter, built using organic chemistry, and consisted of branching which aided in the growth of functional groups on the outside. They were also found to be cross linkers interacting with other polymers, gaining strength and losing flexibility, allowing protein and antibodies to line up, making it easy to detect where a heart attack was taking place. Dendrimers also help create osmotic pressure of a molecule without losing it through a membrane. An interesting part of their structure is a void space which allows for carrying molecules such as drugs. This capacity can make them useful in targeting cancer cells. Heinzelmann has an idea that the ligands could be targeting groups, and the drugs used in cancer treatments could be inserted in these void spaces, then the dendrimer could be directed to the area of cancer cells, centering the drugs on them, killing them. Another idea is that the dendrimers can be modified to carry a genetic code involving siRNA-small interfering RNA.

Heinzelmann then focused on the career possibilities for chemistry majors, aside from the usual route undergrads take. Himself only obtaining a Bachelors in Chemistry, Heinzelmann stressed that it was not necessary to earn a PhD in science to achieve a fulfilling career life in chemistry. In the business world, there is a need for marketing, supply chain management, sales, and regulatory positions with the government. An open mind keen on learning proved to be a key factor in success.

Though there was some lack of fully defined explanations on several things, Heinzelmann did have all the data required to make a clear case for the DNT product value and progress. Furthermore, Heinzelmann understood the material he was discussing and answered the questions that were asked clearly and with specific and useful responses. Overall the lecture was well presented, and put together.

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Joseph Heinzelmann visited us from Mount Pleasant, Michigan from Dendritic Nanotechnologies, DNT.  At Dendritic Nanotechnologies Joseph Heinzelmann is a product manager.  Joseph in in his sixth year of experience experience at DNT, these experiences include production Dendrimers, Business Development and Production Management.  Joseph has played a very important role to continual development of the PAMAM and PRIOSTAR production lines at DNT.  Joe received a BS degree in chemistyr from Albion College in Albion Michigan in 2004 and then received an MBA in 2009 from Northwood University.  Joe is a happily married man with a two year old daughter.

Joseph Heinzelmann’s work with DNT is solely focused on Dendrimer production.  There are two classes of dendrimers, the Priostar and the PAMAM.  The PAMAM is the dendrimer that Joseph spoke with us about on thursday. A major question is what is a dendrimer.  A dendrimer is carefully architected and highly organized.  Dendrimers are very limited in there size.  They tend to range in size from 1-10 nanometers.  These dendrimers are built via organic chemistry.  These dendrimers can be created to be larger in size and density.  However, the higher the density the more brittle it makes the product.  These dendrimers are being used to create a type of cancer killing drug carrier.  Meaning that the dendrimer is like a capsule that will carry the cancer killing drug around the body and then with ligands being attached to the exterior of the dendrimer, allowing the cancer cells to be targeted.  This study and development is key because this could lead to a cancer cure.  The cancer killing drug would be placed within the void space in the generation 4 to generation 6 dendrimers.  However, as feasible this idea is it will not be available to the market for some time due to a lack of research in the field and funding from the government to continue to studying.

Joseph Heinzelmann was a great speaker.  He spoke loudly and clearly and was very energetic and knowledgeable about the topic he presented.  Due to a lack of time I was not able to ask all of my questions about the dendrimers.  I would really like to know if dendrimer is cancer specific?  How feasible will it be to get these dendrimers to have the cancer killing drug attached to the dendrimer?

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The speaker of Chemistry Seminar held in March 4, 2010 was Joseph Heinzelmann, who has 6 years of experience at Dendrictic Nanotechnologies (DNT). As a product manager, he has worked for business and development of Priostar and PAMAM dendrimers at his company. So, during his seminar he emphasized the importance of marketing and business in chemical industry. The chemical industry has shown rapid growth, and the U.S. chemical output is $400 billion a year.

In addition, through his presentation, I could learn more about dendrimers. DNT produces two product lines of dendrimers, Priostar and PAMAM, and both dendrimers have endless possibility. Dendrimers are highly branched polymer molecules consisting of core molecules, branch structures usually until fifth generation, and surface groups of several kinds of ions. The surface of dendrimers can be modified, and void space between generation structures is capable of carrying molecues like drugs or imaging agents. Therefore dendrimers can cover a very wide range of application area including druge delivery, siRNA and DNA transfection vectors, surface modifier for conjugating antibodies, peptides, or dyes, and so on.

In spite of these a lot of advantages, in fact, dendrimers are not yet used in therapeutics as drug carriers for treatment of cancer. There are several significant problems that need to be solved. At first, researchers face manufacturing problem, and the safety of dendrimer is required to be studied before dendrimers are used to cure cancer. In addition, drug delivery takes a long time and a lot of money.

To my non-science friends, I would say that dendrimer is a highly branched spheroid or globular molecules that have a lot of applications in life sciences research, industrial, and pharmaceutical areas.

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The presenter for this week was Joseph Heinzelmann. He completed his Bachelor’s of Science in Chemistry and began working at Dendritic Nanotechnologies (DNT). Heinzelmann is currently a DNT products manager, whose main focus of research is PAMAM dendrimers. A dendrimer is a highly organized polymer built from repeating branching made in order of molecular complexity. PAMAM dendrimers represent an exciting new class of macromolecular architecture called “dense star” polymers. Dendrimers have a high degree of molecular uniformity, narrow molecular weight distribution, specific size and shape characteristics, and a highly- functionalized terminal surface. The manufacturing process is a series of repetitive steps starting with a central initiator core. Each subsequent growth step represents a new “generation” of polymer with a larger molecular diameter, twice the number of reactive surface sites, and approximately double the molecular weight of the preceding generation.

Nomenclature or dendrimers begins with branching then the surface groups. Dendrimers were found to be 1-10nm in diameter, built using organic chemistry, and consisted of branching which aided in the growth of functional groups on the outside. They were also found to be cross linkers interacting with other polymers, gaining strength and losing flexibility, allowing protein and antibodies to line up, making it easy to detect where a heart attack was taking place. Dendrimers also help create osmotic pressure of a molecule without losing it through a membrane. An interesting part of their structure is a void space which allows for carrying molecules such as drugs. This capacity can make them useful in targeting cancer cells. Heinzelmann has an idea that the ligands could be targeting groups, and the drugs used in cancer treatments could be inserted in these void spaces, then the dendrimer could be directed to the area of cancer cells, centering the drugs on them, killing them. Another idea is that the dendrimers can be modified to carry a genetic code involving siRNA-small interfering RNA.

With all of these plans for dendrimers there is the problem of manufacturing. They must be taken through a regulatory process, get FDA approved, solve safety issues, and the drug delivery takes time. Purity has also been an issue, the dendrimers cannot touch each other or they will create dimmers. One must also use large excess of reactant about 100 equivalents per surface. Heinzelmann then concluded that PAMAM dendrimers have great promise, endless possibilities, trouble securing funding, and the manufacturing process must be improved and that there are still new classes of polymers still being developed. He also gave very useful information about the future careers awaiting chemistry majors and believes that one must stay open minded and keep learning.

During this presentation Heinzelmann’s audio was well, made eye contact with the audience, went through the slides quickly and finished on time. I found this topic to be very interesting and many students seemed to be engaged. There were many questions answered at the end and all of these questions were answered well. This presentation did encourage me to learn more about PAMAM dendrimers and I wouldn’t mind doing summer research on this topic. I wasn’t really encouraged to go to the speaker’s school for graduate studies, but Heinzlemann didn’t really speak about it, but he was available to answer question if one was to ask at the end of the presentation.

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There was a presentation on March 4, 2010 about synthesis, application and commercial development of dendrimer. The presentation was given by Mr. Joseph Heinzelmann who is the product manager of dendritic nanotechnologies, Inc. The presentation was very impressive because it was full of informative contents about business in chemistry as well as scientific contents. He started the seminar introducing the basic knowledge of dendrimers. What properties do dendrimers have? How are they synthesized? What application can they be used?

Mr. Joseph Heinzelmann told us that dendrimers are highly organized polymers which are built from repeating branching sides. As the complexity of the molecules, there are a number of different types. Dendrimer is composed of a core molecules, interior rod, and surface group. The question I asked to him was that which molecules can be a core molecule. He answered that any molecule is able to be a core molecule of a dendrimer and the company he is working for is using ammonia group for the core molecule. One of the applications of the dendrimer is to carry molecule like drugs or imaging agents. Nowadays, the treatment for cancer is MTX which blocks the pathway of synthesizing Tetrahydrofolate from Folate. However, the weak point of MTX is that it is non-selective. It means that MTX also affect on normal body cells which grow rapidly such as hair cell. If dendrimers carry MTX to only tumor cells, they will be the best way to treat cancer.

I would tell my friends that the presentation was a good chance to learn how a company based on chemistry is operated and how dendrimers can be used.

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Chemistry seminar on March fourth was presented by Joseph Heinzelmann. He is a product manager for Dendritic Nanotechnologies Inc. I would describe this seminar to friends and family as a description of the applications of new polymers called dendrimers, and new insight into the use of a chemistry degree. The presentation consisted of two parts. The first described dendrimers and a new type of PAMAM dendrimer. The second part of the presentation focused on the use of a chemistry or biochemistry degree.

A PAMAM dendrimer is an acronym for a polyaminoamine dendrimer. These are a new class of polymers being developed that begin with a bi-functional core molecule. It is hoped that dendrimers will be used in cancers treatment as they can carry ligands that locate cancer on their surface and deliver drugs to kill the cancer from the void of the dendrimer. One complication with these polymers is that they cannot touch or they become dimers. A great deal of excess reagent must be used to prevent this from happening. I asked if further research was being done to reduce the waste of reagent. Heinzelmann informed me that they are looking at covering the active groups that cause the dendrimers to combine.

The presentation helped to bring some new ideas to us about what can be done with a chemistry or biochemistry degree. Often we assume that we will all either go into some kind of medical field or get a doctoral degree and focus on research. This presentation helped to remind me that there are a lot of other options for students getting chemistry degrees. Heinzelmann mentioned that in the drug and chemical industry there are jobs like sales, and product managing. He also suggested some professions I would not associate with chemistry majors. The main one that surprised me was getting a Juris Doctor, JD, to go into patent law. I currently have quite a few friends who are pre-law and all of them are English or political science majors.  I am personally not interesting in using my biochemistry degree to get a JD, but it’s always good to be informed of carrier choices I wouldn’t necessarily have thought about.

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Joseph Heinzelmann brought into focus the business aspect of chemistry this week. He is the product manager of Dendritic Nanotechnolgies, Inc. (DNT), a part of a larger company, Starpharma, based in Australia. Starting off in organic synthesis, Heinzelmann moved on to work as a business manager before assuming his present role at DNT.

Two product lines that Heinzelmann is responsible for are Priostar Dendrimers and PAMAM Dendrimers. Dendrimers are spherically shaped molecules that can be divided into four parts: the core, generation, interior void, and the surface groups. The core can be anything with at least 2 amine groups. Each layer of branching, called a generation, is appended on through a Michael’s addition reaction. The number of generations, how large the dendrimer can become, is determined by the interior void, the free space between the branches that decreases with each branching. The void space is considered around the 3rd or 4th generation – drugs or imaging agents can be inserted in these compartments, like luggage for the dendrimer. Constituents of the surface groups determine the actual chemistry of the dendrimer as it composes the outermost region of the molecule. Dendrimers can range in size from 1-10 nm and the size determines where it can travel in the body, how the body will manage it. Because they are basically plastic, dendrimers are excreted from the body normally (through the kidneys).

Some of the dendrimer’s interesting characteristics show promise as a biomedical solution. Cross linkers on the surface create high density reaction area and the internal structure provides strength without the loss of flexibility, a common problem with most polymers. Many possibilities lie in surface modifications to improve the manner of interaction with other reagents. For example, during a heart attack the body secretes certain products. Dendrimers can bond to antibodies and antigens in blood and because they can be lined up, it is easier to determine whether the person is having a heart attack or if they are suffering from heart burn.

Hopeful applications for dendrimers may be in fighting cancer. Most therapy for cancer involves the killing of healthy cells. Incorporating existing cancer drugs with the “smart” nanotechnology of dendrimers, the cancer cells can be targeted avoiding the deterioration of healthy cells. Imaging agents can also be incorporated and with MRI scanning the progress of the drug can be observed in real time. Gene therapy is another possibility since dendrimers can be made the same size as siRNA (small interfering RNA) they would be able to carry genetic coding. However, like many hopeful patents, dendrimers face the problem with manufacturing problems, government restrictions, financial restrictions, and safety issues.

Another issue Heinzelmann wanted to focus on was the career possibilities for chemistry majors, aside from the usual route. Himself only obtaining a Bachelors in Chemistry, Heinzelmann stressed that it was not necessary to earn a PhD in science to achieve a fulfilling career life in chemistry. In the business world, there is a need for marketing, supply chain management, sales, and regulatory positions with the government. An open mind keen on learning proved to be a key factor in success.

Heinzelmann’s presentation topic was not wholly new as we have had other seminars on dendrimers. However it was refreshing to have the basic foundation that Heinzelmann gave on dendrimers, as the other speakers assumed that we had this knowledge leaving the audience a bit befuddled. Since we are reaching our last guest speakers, a slew of questions bombarded Heinzelmann from all across the amphitheater. Many of my own questions were asked and answered, although it remains unclear what the present stage dendrimers are at in relation to being in practical use. During the presentation, Heinzelmann mentioned that due to the discouragement of ever getting dendrimers past that large mountain of regulations and testing, many people left the project. In relation to cancer, I wondered if dendrimers really are the future to cure cancer.

Laymen’s Summary of Seminar: Dendrimer’s root word is Greek for ‘tree-like branching’. The molecule looks like a sphere, or even better, a strange planet covered with tall trees, something you would see in the world of the Little Prince. Dendrimers can carry other small molecules, such as drugs, in the pockets of space between the branches. In the body, the size of the dendrimer determines where it can go, giving us more ability to decide what to do with it. Side note: You do not need a PhD in science to be great at chemistry or have a great career in the chemistry world.

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This week’s chemistry seminar was presented by Mr. Heinzelmann, a current product manager at Dendritic Nanotechnologies (DNT). After obtaining a B.S. degree in chemistry from Albion college, he thought deeply about his future career working as a chemist. He decided working in a lab alone for many hours was not a type of thing he wanted to do for the rest of his life, so he moved onto obtain an MBA from Northwood University. He has been  working at DNT for 6 years, and he demonstrated to us chemistry major undergraduate students that there are many more ways we can take after we graduate depending on our own interest. The title of his presentation was “Synthesis, applications and commercial development of dendrimers.”

I learned that DNT is owned by Starpharma. DNT has 69 patents issued and owns two product lines of dendrimers. Manufacturing steps of DNT were as follows: prepare bifunctional molecule -> attach methyl ester -> attach ethelyne diamine. The core molecule has four surface groups, and each additional generation (attaching ethelyne diamine) doubles the surface groups. Thus, dendrimer starts with 5.2nm in size, but grows bigger as its generation increases. In the middle of dendrimer, there is a room for solvent or other molecules to get in, and this room serves its purpose well when used to deliver cancer treating drugs for instance.

My questions during his seminar included: 1) How long do you think it will take for this dendrimer to be used in real life as a cancer delivering agent? 2) What is the biggest generation you have created and does it grow in size forever? and 3) How does different sized dendrimer find its way to the right place in the body?

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Our lecturer, Joseph Heinzelmann, product manager from Dendritic Nanotechnologies was able to give a presentation on not only dendrimers, but also on the chemistry industry and career options that is relevant for us. I enjoyed this presentation because he was able to explain clearly about the dendrimers.

His presentation focused on the PANAM dendrimer. He made a statement that dendrimers are carefully architectured polymers that consist of a core and several layers categorized by generations. In addition to that, dendrimers can have many different surface groups. It was named dendrimer for its treelike branching. Usually dendrimers are 1-10nm and built with some organic chemistry reactions. I learned that dendrimers do a variety of things. They can be crosslinkers, have suface modification, and carry drugs in their void spaces.

Overall, I enjoyed this seminar because I was able to learn more about the chemical industry. It seems like an interesting area of chemistry if you do not want to be stuck in the lab, as Heinzelmann put it. In this seminar we had an abundance of questions as we are winding down to only a few more seminars left. Because of this, I was able to learn a great deal more about dendrimers.

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The seminar that was held on March 4, 2010 was “Synthesis, Applications and Commercial development of Dendrimers.”  The guest speaker for this presentation was Joseph Heinzelmann who graduated from Albion College with B.S.in Chemistry.  Following that he focused on organic synthesis and started working on dendrites.

Joseph Heinzelmann started his presentation with DNT/ Starpharma after he introduced himself.  Starpharma is the $150 M market Cap Brotech Company in Melbourne. DNT is mostly involved in the production and study of dendrimers. Dendrimers are carefully architected, highly organized polymers. They are also nomenclature, composed by small core, inferior void and surface group. Furthermore, they are cross linkers which work as surface modification and ball bearing. Additionally, void space allows for carrying molecules like drug or imaging agents.

More interesting thing is that in nanotechnology, the size helps to ligands could be targeting group, and drug could be things that kill cancer. Moreover, some dendrimers can be modified to carry genetic code. Therefore, dendrimers can be useful treatments for various different diseases such as cancer and heart attacks. However, it cannot be used in prescription because it has not been proved to be safe. Now, he is working on these problems hoping dendrimers to be useful drug that kills cancer cell not harming any other healthy cells.

Overall, this presentation was pretty interesting and attractive because a lot of people are struggling with cancer and people who have cancer also struggling with side effects from the cancer drug or treatments. I had questions for this seminar and one of them was how the dendrimers structurally related like bonding. He answered with drawing bonding and mechanisms on the board.

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The presentation this week (03-04-2010) was titled “Synthesis, Applications and Commercial Development of Dendrimers”. It was given by Joseph Heinzelmann, who is the product manager for DNT/Starpharma. Joseph graduated high school in 200, then went to Albion College.

His company specializes in two different product lines, specifically dendrimers. Dendrimers are carefully architected, sphere, small polymers. The size of these dendromirs range between one to ten nano meters, and are built using basic organic chemistry. Dendrimers can be useful treatments for all sorts of different diseases, including cancer and heart attacks. Joseph is hopeful that these dendrimers will be able guide cancer killing drugs specifically to cancer cells, and not destroy other healthy body cells. Dendrimers can also help enhance heart attack detectors, which is very important. Because of the specific shape of the dendrimer, in any type of filtration device, or membrane, it can be used to create an osmolarity, which in some situations can become very important. The only problem to this research, is that it is old. Dendrimers are not used in perscription drugs because it has not been proven to be safe. Currently, Joseph is trying to find a solution to this and the issue of the budget. Joseph Heinzelmann presented his work very effectively, and kept his audience attentive. He spoke clearly and without an accent. Many questions followed the question and answer session, which he answered effectively.

Overall, I thought the presentation was interesting to listen to. The fact that this technology could be used to treat cancer, and detect heart attacks was very interesting. Although I am very interested in cancer treatment, this type of technology did not appeal to me. It is not something that I would like to spend my time researching.

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The lecture this week was about the synthesis, production, and uses of dendrimers. The speaker was Joseph Heinzelmann, Product Management, Dendritic Nanotechnologies, Incorporated. DNT is a subsidiary of Starpharma Holdings Limited, and is mostly involved in the production and study of dendrimers.

The topic delivered this week was fairly interesting in that it not only included information concerning the synthesis and production of a new technology that could potentially have applications to curing cancer, but it also included information concerning job potentials in the field of chemistry. One of the things that I learned from this lecture was that the spherical structure of dendrimers give them a larger surface area, allowing them to have a higher density for reactions. Another thing that I learned from this lecture was that dendrimers provide a better function than other polymers because of their spherical nature. This is because the spherical shape of the dendrimer prevents it from escaping through the porous materials in the body, whereas polymers are typically long skinny chains that can easily fit through pores. One thing that would be interesting to find out more about is how dendrimers are synthesized, more specifically how the spherical shape of a dendrimer is formed.

If I were to describe the topic of this lecture to one of my non-science friends, I would probably say that the lecture was about how a chemical that has potential in fighting cancer is created and produced, and how the companies that make it market the product to other companies.

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Joseph Heinzelmann came to talk to us about some of the business sides of a degree in chemistry. He is a worker for Dendritic Nanotechnologies, Inc, or DNT, where he began working in 2004. This talk was very interesting, first with the subject matter on dendrimers, then with the insight into the different options that are out there for graduates with chemistry degrees.

A dendrimer is a molecule that is made up of a core, and has branches coming out of it creating some very large molecules. There are surface groups on dendrimers that are used for reacting with destinations, and there are void spaces within the molecule where substances can be packed and carried. A current use for dendrimers is to find out if an individual is having a heart attack. Some future uses include work with cancer and gene therapy. In the case of cancer, dendrimer would be loaded with cancer drug and injected into the body. The surface groups would be made so that they will interact with the cancer wherever it is in the body, so the dendrimer would be caught and the drug would be unloaded before the dendrimer would be removed from the circulation. The dendrimers that I have just described and what most of Heinzelmann’s talk was about are the PAMAM dendrimers. These are made by repeated action of starting with the core molecule and adding methyl acrilade, after this ethylene diamine is added. These two steps are repeated, each time adding another generation until the desired size of the dendrimer is established.

I would describe this talk to a non-science friend as being partly about creating carrier molecules for anti-cancer drugs and partly about the business side of chemistry.

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This week’s speaker was Joseph Heinzelmann, an employee of DNT.  DNT is a subsidary of Starpharma, a world leader in dendrimer production.  Dendrimers are carefully architectured, highly organized polymers that are 5.2 nanometers long.  Dendrimers have a core, with concentric circles called generations.  As the dendrimers branch out, void spaces are created that can be occupied by air or solvent.  Drugs can also inhabit the void spaces, and the dendrimers can transport these drugs.  One practical application of this is for dendrimers to carry cancer killing drugs directly to cancer cells.  Normally, chemotherapy kills healthy cells as well as cancer cells.  But, if the transport techniques are perfected, then cancer treatment can work without killing normal cells.

Although dendrimers seem like the holy grail of cancer treatment, they are not easy to synthesize.  They also have some safety issues that have not yet been worked out, and the synthesis is very expensive.  For the synthesis of dendrimers, a bifunctional molecule is used as the starting point, and the dendrimers branch out through 1,4 addition of amines.  But, if the dendrimers touch each other, they will form dimers.  So, pure dendrimers are difficult to obtain.  One solution to this problem is to add a motherlode of reactant, 100 equivalents to a surface group.  Generation 5 dendrimers have 128 surface groups, so it is not difficult to see how expensive synthesis can get.  Although the dendrimers have great promise and endless possibilities, there is not enough funding to fully explore them.

Despite the limitations in dendrimer synthesis, I found this presentation very interesting.  It was easy to understand how dendrimers could be used as an effective cancer treatment.  It seems that the cure for cancer is not that far off.  One question I have is what generation of dendrimer is required for cancer cell targeting?  Secondly, are all dendrimers based on organic chemistry, or do some inorganic dendrimers exist as well?  Finally, what is the average amount of time needed to synthesize a dendrimer?  I would definitely be interested in learning more about these molecules.  In summary, this presentation was about a complex class of molecules that could be used to specifically target cancer cells.

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This week was our first time in Chemistry Seminar for 2010, and everyone appeared to be a tiny bit groggy and perhaps not totally ready to jump in and ask 6 questions. Whether your burden is Chemistry Seminar or a frightful bone injury requiring polyaryletherketone implants, life does go on–sometimes without you!

And with that painfully transparent intro, I segway into the talk given by our guest speaker in ChemSem this week, Ryan K. Roeder. Roeder has been conducting research into different ways in which to increase the strength of implants used in bone. In contrast to the types of implants used orally for artificial teeth, bone implants are not made from stainless steel or any kind of mixed transition metal alloy. In addition, this method does not employ the traditional procedure of removing bone from elsewhere in the patient to use in place of lost or decaying bone, a procedure known as autografting.

Rather, Roeder’s work takes him into the field of composite implants which utilize materials capable of expanding and contracting in a very similar fashion to that of real bone. Roeder’s work has led him to use an aromatic class of polymers known as polyaryletherketones. Traditionally, these were used as simple “pins” in bone. However, Roeder mixed this older method with a newer one which involves the diagonal implantation of these composite rods. The mere physics of the procedure validates its usefulness. Multiple randomly-oriented diagonal rods will increase the resistance of the implant to longitudinal tension, thus strengthening the connection while still using the same composite. This technology could improve a proven science for orthopedic patients everywhere.

I felt that the presenter did a decent job of presenting the material. He had the attention of the students much of the time because of the simplicity of the chemistry and the abundance of healthcare-bound members of the audience. I felt that this presentation was slightly less rooted in chemistry than some of the others, but it was still applicable to those present.

To the layperson, this seminar was about new ways to use materials in bone surgery to make them work better.

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This week we in Chemistry Seminar were privileged to hear from Mary L. Kraft, Ph.D. It’s always exciting to have a fellow biochemist as our guest speaker, and Dr. Kraft did not disappoint. Her talk was on the distribution of sphingolipids in the plasma membrane of intact cells, and her research showed that, as opposed to the Fluid Mosaic Model of the plasma membrane, research postulated that sphingolipid distribution is neither normal nor random, but rather clumped.

The plasma membrane is composed of a cacophony of various lipids, steroids, proteins and other organic materials. A long-time-standing suggestion used to be that the plasma membrane consisted of a bilayer of phospolipids and other membrane elements which can, in their respective layer, move about freely. Viewed superficially, this fluid-like membrane appeared to be a mosaic of organic compounds, hence the Fluid Mosaic Model.

The presence of sphingolipid clumping, however, as observed in Dr. Kraft’s research, showed that the dispersion of membrane elements is not exactly random. Utilizing N-15 as a marker, Kraft’s group reconstructed the membrane of a fibroblast cell. N-15, which primarily marked for sphingolipids, was shown as glowing yellow spots on the surface of the cell membrane. In order to ensure these colors were not simply the result of noise from non-cell contaminants in the sample Kraft did additional testing of cells containing a large amount of C-13, which was expected to appear in normal distribution throughout the cell membrane in the fatty acid tails of membrane lipids. This hypothesis wasn’t overturned by experimental evidence.

I later spoke with Dr. Kraft, commenting on the proximity of N-14 clumps to the cell nucleus. Dr. Kraft affirmed me by stating that she, too, had seen this pattern. I thought that perhaps this could suggest the correlation of sphingolipids with protein secretion from cells or with the release of various steroids associated with the smooth ER. These certainly were possibilities.

I felt Dr. Kraft was a very personable presenter. She was very apt at answering any questions we had for her, and she was willing to take extra time following the presentation to answer some additional questions I had for her. This research seems to be very promising and can hopefully lead to important details of membrane transport and cellular communication.

To the layperson, this seminar was about the body’s cells and whether their coating materials are arranged at random or in specific sections.

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This week’s seminar was entitled Visualizing Lipids in Plasma Membranes.  The speaker was Dr. Mary L. Kraft, a biochemist and an assistant professor at the University of Illinois. She received her bachelor’s degree from the University of Illinois in Chicago and her PhD from the University of Illinois at Urbana-Champaign.  She then did her postdoctoral studies at Stanford University.  The speaker was really interesting.  She gave a background that made the presentation easy to follow.  The topic was also really interesting.

One of the new things I learned from this seminar was that virus envelopes contain more cholesterol and sphingolipids than the host cells.  Another thing I learned was that how well proteins work depends on the surrounding lipids.  I also learned about secondary Ion Mass Spectroscopy (SIMS).

The other students seemed to be attentive during the seminar.  There were also a good number of questions at the end, and the speaker answered all of them well.

This seminar did encourage me to look into learning a little more about the topic.  However I don’t think I would be very interested in doing any research on it, nor would I be interested in attending the speaker’s school for graduate studies.

The reason I think that this seminar was so interesting is because the speaker was excited about the topic and because of the biochemistry content.

If I were to describe this seminar in one sentence it would be “determining how the lipids in the membrane of fibroblast behave.”

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This week’s presentation was done by Dr. Mary L. Kraft. The title of her presentation was “Direct visualization of heterogeneous sphingolipid distribution in the plasma membranes of intact cells.” Dr. Kraft is currently an assistant professor of chemical and biomolecular engineering at the University of Illinois – Urban Champaign. Her research on plasma membranes had many biomedical applications such as facilitating the treatment of viral infection. Her presentation was easy to follow and understandable.

From her presentation, I learned that plasma membranes contain a region which is rich in sphingolipids and cholesterol, although they are often described as “uniformly distributed.”  In her research, she used mass spec to collect the readings of entire surface of the plasma membrane that is being studied. However, since its resolution was low, she used secondary ion mass spec to obtain higher resolution of the “picture.” In order to observe the distribution of real cells, C12 and N15 ions were used in place of original elements in sphingolipids. Her finding was that there is a sphingolipid-rich micro domains, and this region was found in all the other plasma membranes that were tested, although the location is not exact. All cells showed similar looking domains.

My questions during her presentation included 1) You used C13 and N15 in your research, is it possible to use other isotopes such as deuterium? 2) Can there be any problems with using isotopes instead of original element? 3) what led you to study plasma membranes? and 4) what are some of the practical applications of this research other than treating viral infection?

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