Summary

On February 2016, me and other 8 students from different laboratories in the Departemnt of Biological Sciences visited the University of Seoul for a week in South Korea. During our time there we had a very good opportunity to improve our communication and collaboration in an international environment by participating in different experiments, sometimes very different from our own research like in my case.
We also had the opportunity to present our own research at a poster session celebrated on Wednesday 17^th. I enjoy answering the interesting questions that other students  made me.
All the week was a great experience, both academically and personally as I was fortunate to make new friends and connections in a new place.

TMU-UOS exchange: University of Seoul

TMU (Tokyo Metropolitan University) conducts every year a short students exchange of one week with the UOS (University of Seoul).
In November 2015 (last year) several students from different laboratories from the Department of Life Sciences came to visit TMU and in the laboratory of Animal Ecology we showed them some of our experiments and we explained the research that we conduct.


Image: Tama Science Forest (多摩森林科学園) where the feeding behaviour of the Japanese Giant Flying Squirrel (ムササビ) (Petaurista leucogenys) is study.

Now, in February 2016, 9 students from different laboratories in the Department of Biological Sciences, we are visiting South Korea and the UOS for a week. Here we will have the chance, not only to present a poster with our research but also to participate in the day to day routine of the laboratory that we have choose, in order to understand the investigation that they are doing.


Image: campus of University of Seoul

TMU-UOS exchange: Nano Bio Interfaces Laboratory

The research conducted at UOS is mainly focus on molecular problems, involving chemistry, physics or detection of proteins or other molecules.


Image: Laboratory at UOS

In the case of the laboratory that I am visiting (NanoBioInterfaces laboratory), they use gold nano-particles to detect or study some phenomena. Golden nano-particles are easy and cheap to produce, and they present colorimetric properties and a characteristic spectrum so they can be use as model or as detector to study different phenomena.

As part of my participation in the laboratory, the two students of Master there, explain to me their respective investigations and I could do the basic experiments that they conduct and that I will explain below.

TMU-UOS exchange: Determination of protein aggregation by colour with nanoparticles

*This investigation is publish at Hye Young Kim and Inhee Choi Ultrafast colorimetric determination of predominant protein structure evolution with gold nanoplasmonic particles; Nanoscale, 2016,8, 1952-1959 DOI: 10.1039/C5NR06517H.


Imagen: Colorimetric differences between gold nanoparticles of different sizes and shapes.

The diseases that present malformation of proteins tend to accumulate those proteins along the time producing harmful aggregates. But study them is not easy as the formation of this aggregates requires long periods of time, both in the sick body and under simulated situations at the laboratory.

In the research of Hye Young Kim at the NanoBioInterfaces laboratory of the University of Seoul, gold nanoparticles are use to simulate this protein aggregates as if they were the protein themselves.


Image: Gold nanoparticules with different sizes (source)

The first experiment I did was to synthesize new nanoparticules with a determine color: I choose a star-shape that shows as blue colour.
        

Image: from gold spheric nanoparticules, I synthesize new star-shape nanoparticules (source of the second image)


Image: the result

But, now that I have newly synthesize nanoparticles, what do I used them for? We can apply them to easy and quick detection of protein aggregation in the sample through colour, so I used them with a peptide solution to observe the colour change.


Image: in a few moments I could observe a colour change in the sample. The detail correspond to the original paper of this research that was reference above.

TMU-UOS exchange: Detection of hydrogen peroxide by chytochrome C and nanoparticles

*This investigation is publish at Yura Kim, Ji Youn Park, Hye Young Kim, Minzae Lee, Jongheop Yi and Inhee Choi A single nanoparticle-based sensor for hydrogen peroxide (H₂O₂) via cytochrome c-mediated plasmon resonance energy transfer; Chem. Commun, 2015,51,15370-15373 DOI: 10.1039/C5CC05327G.


Image: Microscopy and detection of the gold nanoparticles on the screen

Again, this research is link with easier and faster ways of studying and detecting potential harmful molecules in the body. In this case is the H₂O₂. H₂O₂ is a ROS (reactive oxygen species) generated naturally in the cells as a by-product of cellular metabolism, and is associated with signalling for apoptosis and proliferation. It is also an oxidizing agent and high levels of H₂O₂ in vivo will induce cellular damage.

Many methods are used to detect different concentrations of H₂O₂: optical techniques (fluorescence, luminescence and absorbance), non-enzymatic electrodes (redox active materials) and gasometry.

The new method develop by the laboratory of professor Inhee Choi uses a single nanoparticle and cytochrome c mediated plasmon resonance energy transfer (PRET). The cyt-c will be reduce in the presence of oxidants and this is clearly detected as the absorption spectres are very different (in the next image).


Image: (A) Illustration of quenching dip in Rayleigh scattering spectrum of a single nanoparticle induced by plasmon resonance energy transfer from the nanoparticle to Cyt-c. (B) Scheme showing dynamic spectral change in the fingerprint quenching dip of a single nanoparticle based on changes in the redox state of Cyt-c induced by H₂O₂. (C) Configurations of a dark-field microscopy combined with a spectrophotometer and a sensor chip for collecting single nanoparticle spectra upon exposure to H₂O₂. (Source)

To study the samples I prepare, I fist observe just the gold nanoparticles, then I add water for control experiment and then I add cytochrome c to observe the variation on the spectres.

TMU-UOS exchange: Conference and poster session

One of the main goals of the student exchange is, bedside learning through the participation on the laboratories of Seoul University, the display of our own work. This was done through a conference and a poster session on February 17^th.

The first conference was done by our TMU accompanying professor, Doctor Shawn McGlynn that introduced his research on microbial ecology.


Image: Prof. McGlynn in a moment of his conference.

After the conference we had a small coffee break and then we prepared our posters. All TMU students participated at the poster session and some PhD students from UOS also, but non from my host laboratory.

It was very interesting for me to answer the questions of my peers and to try to explain my poster in a simpler but complete way. as the students from UOS were not familiar with the field of ecology.

An interesting detail that I also mention (and that one of the Korean students already knew) was the existence of a species of salamander in the Korean Peninsula. I also learnt to say salamander in Korean: dolongnyong.