Camptothecins are fluorescent compounds which exhibit anticancer properties. A disadvantage which seriously limits application of camptothecins in antitumor chemotherapy is the hydrolysis of these compounds. They convert into inactive carboxylate forms. The process of hydrolysis is inhibited when the molecules of camptothecin are bound to cell membranes. So it is desirable that camptothecins molecules bind easily to membranes. A quantitative measure of drugs affinity to membranes is the association constant. To determine the association constant to membranes the lipid bilayers i.e. liposomes are used as model membranes. In this work affinity of hydroxycamptothecin DB-67 to model membranes is determined. Fluorescence spectra of this analogue change in presence of liposomes: the fluorescence intensity is bigger and besides green band the blue band appears. The spectra of hydroxycamptothecins change over lipids concentration. On the basis of this changes the association constant to membranes is calculated.

Date Published: 6 December 2006
PDF: 7 pages
Proc. SPIE 5945, 14th Slovak-Czech-Polish Optical Conference on Wave and Quantum Aspects of Contemporary Optics, 59451J (6 December 2006); doi: 10.1117/12.638941

Published in SPIE Proceedings Vol. 5945:
14th Slovak-Czech-Polish Optical Conference on Wave and Quantum Aspects of Contemporary Optics
Anton Štrba; Dagmar Senderákova; Miroslav Hrabovský, Editor(s)