Photoactivity inhibition of zinc phthalocyanine choline derivatives (Cholosens) by sodium alginate

• Published in: Dyes and pigments 2018-08, Vol.155, p.42-50
• Main Authors: Sheinin, Vladimir B., Kulikova, Olga M., Lipatova, Irina M., Yusova, Anna A., Koifman, Oscar I.
• Format: Article
• Language: English
• Subjects: Cholosens; Fluorescence quenching; PDT photosensitizer; Polyelectrolyte complex; Sodium alginate; Synchronous UV-Vis and fluorescence titration; Zinc phthalocyanine choline derivatives
• ISSN: 0143-7208; 1873-3743
• DOI: 10.1016/j.dyepig.2018.03.026

With the aim of achieving supramolecular structures with controlled phototoxicity of photosensitizer the features of formation, stoichiometry, spectral and aggregation properties of alginate polyelectrolyte complex of Zn-phthalocyanine hepta- and octacholine derivatives were investigated. Chlorides of such Zn-phthalocyanine choline derivatives enter into the composition of photosensitizer Cholosens, developed for photodynamic therapy of oncological and infectious diseases. Cholosens cations possessed high, but different resistance to aggregation. In an aqueous solution saturated with sodium chloride, heptacations exist as H-dimers, in contrast to more hydrophilic octacations. Cholosens interaction with sodium alginate leads to a rapid self-assembly of the alginate polyelectrolyte complex with octacations and heptacations H-dimers. At the equivalence point, a jump-like collapse of the polymer coils occurs to form a suspension of the electroneutral nanogel of polyelectrolyte complex. Cholosens cations fluorescence in obtained nanogel is completely quenched. This fluorescence quenching is due to the H-dimerization of heptacathions, and the octacations interaction with alginate environment inside the polymer coil. Result of this work demonstrates the possibility of the Cholosens phototoxicity inhibition, promising for "on/off" systems developing. [Display omitted] •Interactions of Cholosens cations with Cl− and alginate were investigated in water.•These anions cause H-dimerization of Cholosens heptacations, but not octacations.•PEC of Cholosens cations with alginate collapses to form nanogel.•Alginate coil completely inhibits photoactivity of Cholosens.