Jenny's Blog: Summer Research with Ionic Liquids

Jenny's Blog: Summer Research with Ionic Liquids

Hey everyone! I am Jenny Huang, your new STEM Board President. Over the summer, I researched at a physical chemistry lab at Rowan University, which is in southern NJ. For my research project, I explored how ionic liquids affect the effectiveness of the antibiotic polymyxin, which is used to treat Pink Eye.

Ionic liquids, known as "designer solvents", are becoming very popular today as research has shown that ionic liquids can be used for a variety of purposes including extracting energy from algae. Ionic liquids may also improve the effectiveness of antibiotics, the things you eat when you have a bacterial infection. This is exactly what I explored this summer: Can ionic liquids improve the effectiveness of an antibiotic called polymyxin.

Like table salt (NaCl), ionic liquids are made of two pieces: a positively charged molecule and a negatively charged molecule. However, because ionic liquids are very heavy molecules, they are liquid at room temperature rather than solid like NaCl. For instance, NaCl has 2 atoms and a molecular weight of 58.4 g/mol while an ionic liquid called 1 Butyl-3-methylimidazolium tetrafluoroborate (C₈H₁₅BF₄N) has 29 atoms and a molecular weight of 226 g/mol.

You've probably heard of antibiotics before and you've probably heard of antibiotic resistance.

Some antibiotics, such as polymyxin, work by disrupting the bacterial cell wall:

As more and more bacteria are becoming resistant to the available antibiotics, it is crucial to develop new methods to fight harmful bacteria.

https://www.cdc.gov/getsmart/community/about/antibiotic-resistance-faqs.html

I observed how ionic liquids affect the bacterial membrane (such as whether the ionic liquids cause the membrane to enlarge or shrink) in the presence of polymyxin. To mimic the bacterial membranes, which consists of a phospholipid bilayer, I used the phospholipids to create vesicles.

Now you may ask, how does one rearrange these lipids so that they line up and form a circular vesicle? In short, making vesicles requires a lot of vortexing.

Phospholipids + vortexing = Phospholipids rearrange to form lipids

https://upload.wikimedia.org/wikipedia/commons/thumb/0/01/Liposome_scheme-en.svg/250px-Liposome_scheme-en.svg.png

After I made batches of vesicles, I would put the vesicle solution in cuvettes, these small plastic rectangular containers, and then add polymyxin and different amounts/types of ionic liquids into each of the cuvettes. Then, I would put the cuvettes in the DLS (Dynamic Light Scattering) machine, which scatters light to measure the size of the vesicles.

Some of the equipment I used:

A vortexer: When a test tube is placed on the black pad, the vortexer shakes/spins the liquid inside the test-tube.

Sonicator: This instrument ensured that the vesicles are the same size.

A cuvette with some vesicles (the blurry substance) and ionic liquids: I transferred the vesicle solution into these containers, so that i can use the Dynamic Light Scattering Machine to measure the sizes of the vesicles.

Dynamic Light Scattering (DLS) machine & computer screen:

Fun things!

^This was supposed to be some sort of fridge

The view from the lab

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Overall, I enjoyed the lab environment and especially meeting new my labmates and professors. Also, the nearby restaurants sold some good food. One of my favorite moments was learning how to measure a precise amount of chloroform. Instead of directly pouring the liquid into a graduated cylinder, which is not as precise as other containers, I had to first take a clean, dry volumetric flask and rinse the flask with the chloroform. Then, since I needed a small amount of chloroform, I used a pipette to fill the volumetric flask up to a certain line. Since chloroform emits fumes, I measured the liquid under a hood.

Research is fun and makes you think critically. If you have any questions about research and finding internships, please contact montystem@gmail.com!

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-Jenny Huang Summer 2016