Nanochemistry and biotechnology
PECULIARITIES OF UPTAKE CHLORIN e6 DERIVATIVES BY DEXTRAN-GRAFT-PNIPAM TEMPERATURE SENSITIVE POLYMER
Yu. Kuziv1, V. Zorin2,3, I. Kravchenko3, T. Zorina3, O.Yeshchenko1, 
A. Marynin4, N. Kutsevol1 
1Faculty of Chemistry, Taras Shevchenko National University of Kyiv, 
60 Volodymyrs'ka str., 01601 Kyiv, Ukraine. E-mail:kutsevol@ukr.net
2Belarussian State University, pr. Nezavisimosti 4, Minsk, 220030 Belarus
3International State Ecological Institute named after A.D.Sakharov BSU, Dolgobrodskaya Street, 23/1, Minsk, 220070, Republic of Belarus
4Problem Research Laboratory, National University of Food Technology, Volodymyrska str. 68, 01601 Kyiv, Ukraine

We have studied the possibility of encapsulation of several chlorin e6 derivatives into stimuli responsive copolymer in order to get a potential photosensitizers with controlled release for photodynamic therapy. We tested nanocomposites consisting of polymer with chlorin e6 (Ce6), dimethylether of chlorin e6 (DME ce6) and trimethylester of chlorin e6 (TME e6) by Quasi Elastic Light Scattering, FTIR, Spectral and Fluorescence polarization measurements.The encapsulation of derivatives of these chlorins into water-soluble polymer can prevent aggregation. The photophysical properties of the copolymer/photosensitizers nanocomposites as function of temperature in the region of the conformational transition of polymer matrix have been studied and discussed. It was shown that at low temperatures all photosensitizers interacted weakly with polymer phase. As a result, absorption and fluorescence properties of Ce6 derivatives in aqueous and polymer solutions are practically identical. Heating above Low Critical Solution Temperature has a significant influence on the fluorescent characteristics of non-polar chlorins indicating the binding of DME and TME molecules in the polymer matrix. With the deep penetration of DME and TME into the polymer phase is associated also a significant temperature-dependent increase in the fluorescence polarization degree. Fluorescence characteristics of Ce6 in copolymer solution when heated, remain unchanged, which indicates the lack of possibility for this sensitizer to bind in the bulk of polymer phase. 

Acknowledgment. This publication is supported in part by National Research Foundation of Ukraine, Project 2020.02/0022 “Plasmon hybrid nanosystems "metal-polymer-fluorophore" with enhanced optical response for photonics and biomedical applications”