Nanocomposites and nanomaterials

New lipophilic fluorescein derivatives for molecular imaging
Yakoviv M.V.1, Nosova N.G. 1, Ostapiv D.D. 2, Samaryk V.Ya. 1, 	Varvarenko S.M.1
1 Department of organic chemistry, Lviv Polytechnic National University, 12, Stepan Bandera str., Lviv-79013, Ukraine. 
E-mail: ferensmariia@gmail.com
2 Institute of Animal Biology NAAS, 38, V. Stusa str, Lviv-79034, Ukraine.
E-mail: oddost@ukr.net

Molecular imaging is widely considered as a future for medical imaging. Molecular imaging was defined as the in vivo characterization and measurement of biologic process at the cellular and molecular level. More broadly definition says that molecular imaging is the technique for directly or indirectly monitoring and recording the spatio-temporal distribution of molecular or cellular processes for biochemical, biologic, diagnostic, or therapeutic application. However, only 2 fluorophores were currently approved by the US Food and Drug Administration (FDA) for medical use: indocyanine green (ICG) and fluoresсein [1]. Acylating of the phenolic hydroxyl group(s) in these fluorophores masks their fluorescence. Obtained in this way esters are vital tools for examining biological and biochemical processes [2].
In this regard, the actual task is synthesis of new ester derivatives of fluorescein as promising fluorogens. The particular interest can have polymers of fluorescein and N-acyl derivatives of natural biphasic amino acids.
For this purpose, were conducted the investigations of the irreversible polycondensation by the Steglich reaction. As a hydroxyl-containing comonomer was used the fluorescein and as a carboxyl-containing comonomer – 2- (dodecanoylamino) pentanedione acid. Moreover, for the first time was synthesized the copolyester containing fluorescein as a repeating link.
Such products can be considered as new latent fluorophores, which can provide the delivering function of a photo-active compound to tissues and cells and to study a number of biochemical processes occurring in them.

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2.	Lavis L., Chao T., Raines R. Synthesis and utility of fluorogenic acetoxymethyl ethers // Chem Sci.- 2011.- 2, N 3.- P. 521–530.