課題番号 ：S-15-NM-0076
利用形態 ：機器利用
利用課題名（日本語） ：
Program Title (English) ：CdSe/ZnS Quantum dots micelle for biological applications
利用者名（日本語） ：
Username(English) ：CHINNATHAMBI　Shanmugavel
所属名（日本語） ：
Affiliation (English) ：JSPS

１．概要（Summary ）
Water dispersion of the CdSe/ZnS quantum dots were accomplished by their encapsulation within polyethyleneglycol (PEG)-grafted phospholipid micelles with biotin as a free end. In addition, the micelle formation reduces the cell cytotoxicity and increses the fluorescence signal in the cell. For the separation purpose we added iron oxide nanoparticle in the micelle core. The prepard micelle was used for futher biological applications.
２．実験（Experimental）
We used following equipment for quantum dot micelle characterization. UV-vis spectrophotometer (Hitachi U-2900, Japan) – Optical Characterization and Photo stability TEM-Tecnai G2 F30 S-Twin with an acceleration voltage 300Kv – Particle and micelle observation. Confocal Microscopy – SP5, Leica Microsystems, Germany, Circular Dichroism Measurement – Protein secondary structure analysis.
３．結果と考察（Results and Discussion）
In the present study, water dispersion of the CdSe/ZnS quantum dots were accomplished by their encapsulation within polyethyleneglycol (PEG)-grafted phospholipid micelles with biotin as a free end. In addition, the micelle formation reduces the cell cytotoxicity and increses the fluorescence signal in the cell. This type of micelle easily uptake cancer cells without further modification, because it will enter the cancer tissue through blood vessel holes. The photostability of micelle under ultraviolet irradiation is stronger than free CdSe/ZnS quantum dots. The interaction of micelle with human serum albumin was studied using steady state and excited state fluroescence spectroscopy and the binding parameter was obtained with various temperature. Hydrophobic force and hydrogen bond stabilized the interation between albumin and micelle. Furthermore, we checked cell viabilty and cellular uptake of prepared micelles using the following cell lines HeLa, RAW 267.4 and A549. There is no notable cytotoxicity observed micelle concentration up to 25μg/mL. We observed fluorescence images of micelle using confocal laser scanning microscope. The observed fluorescence images clearly shows the high intensity of micelles after 72h incubation. This methodology demonstrates the huge guarantee of quantum dots as a part of tests for multimodel imagimg and therapy.

４．その他・特記事項（Others）
NIL

５．論文・学会発表（Publication/Presentation）
(1) S.Chinnathambi, X.Pi, M.Xu and N.Hanagata, J.Drug Deliv. Sci. Tec., Vol.29, (2015) p.p.251-260,
(2) S.Chinnathambi and N.Hanagata, 8th International Conference and Exhibition on Pharmaceutics & Novel Drug Delivery Systems, March 07-09, (2016) Madrid, Spain.

６．関連特許（Patent）
NIL