One month Exchange Program Report

Yilin ZHENG (Master Course Student), Fudan University, China
Host Organization: Kyoto University, Japan
Training Supervisor: Professor Motonari UESUGI

Glucose Co-Assembly Hits Screening By Dynamic Light Scattering Measurement

Zheng Yilin

Fudan University, School of Pharmacy
2^nd Year in Master’s Course

Based on group’s previous work (didn’t publish yet), where a focused library of self-assembly compounds was established, we intended to do a further screening for co-assembly hits, which own potential use in diagnosis^[1], drug discovery^[2], and some other unexplored fields. From this point, a pilot study of these self-assembly compounds with glucose^[3], an endogenous compound far exceeding normal level in diabetes mellitus patients, was performed.

Considering the detectable fluorescence of the self-assembly compounds, we measured the particle size by dynamic light scattering (DLS), which is based on the fluctuation of the scattered light intensity^[4].

After a first-round screening (Figure 1), we found that some glucose added compounds size was increased, and some decreased, though most compounds didn’t change significantly. Later, some large particles were observed by microscope. For the hits screening purpose, we still need a second-round validation and more proof. This experiment elucidates that glucose may be able to co-assemble with some specific compounds, which may be used in diabetes mellitus treatment. It also offers an expectation that diseases caused by aggregation may be cured by adding suitable compounds to decrease assemble.

Figure 1. Bar graph of compounds size change ratio.
R2, radius of compounds with glucose loaded detected by DLS;
R1, radius of compounds only.

Experiments

Dynamic light scattering (DLS) experiments were accomplished using DynaPro Plate Reader-II. 20 mM of glucose in PBS was prepared as stock solution. 900 μL of the glucose solution was diluted to 9 mL of PBS, and 80 μL of the dilution was added to 384-well plate. Then 0.8 μL of 5 mM self-assembly compounds were loaded. For measuring the aggregated particle change after adding glucose, we used PBS and compounds only as comparison. After centrifugation, it took 2 h incubation for DLS experiments. DLS measured the size five times as one set and displayed average histogram.

Acknowledgements

I am grateful for Prof. Uesugi and Ms. Vu who provide invaluable advice and guidance. This work was supported by JSPS A3 Foresight Program : Asian Chemical Probe Research Hub.

Reference

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ZHAO R, ZHENG G, FAN L, et al. Carrier-free nanodrug by co-assembly of chemotherapeutic agent and photosensitizer for cancer imaging and chemo-photo combination therapy[J]. Acta Biomaterialia, 2018.
ORGANIZATION W H. Global report on diabetes[J]. Working Papers, 2016.
STETEFELD J, MCKENNA S A, PATEL T R. Dynamic light scattering: a practical guide and applications in biomedical sciences[J]. Biophysical Reviews, 2016,8(4):1-19.