Synthesis and Study of Dextran:ZincAminomethylphthalocyanine Copolymers for Medicinal Applications

Abstract

This paper describes the synthesis and characterization of a new water-soluble zinc aminomethylphthalocyanine: dextran copolymers for medical applications. Mono-ZnAMPc has been synthesized by the hydrolysis of mono-(carboxybenzamidomethyl) ZnPc in an acidic medium using a closed reaction system. Dextran has been modified with cyclic and acyclic carbonate groups using triethylamine as catalyst. The FTIR spectra of the functionalized polymer show absorptions at 1805 cm−1 and 1745 cm−1 that indicated both cyclic and acyclic ethyl carbonate groups. Grafting of dextran to zinc aminomethylphthalocyanine was performed using ethyl chloroformate. The metal phthalocyanine content in copolymer varies in a range of (10–50) wt %. FTIR spectra of zinc aminomethylphthalocyanine:dextran copolymers indicated the appearance of new vibrations at (3300–3450) cm–1 and (1550–1650) cm–1 in the copolymers that confirm the presence of amide bound. It is found that the copolymers containing (10–30) wt % of zinc aminomethylphthalocyanine: dextran, ratio 1: 1, are water soluble. Also, for the solubilization of the copolymer, the DMSO: H2O mixture was used. The UV–Vis spectra of the developed copolymers showed more broadening of Soret and Q absorption bands in water than in the DMSO: H2O mixture. Mono-aminomethyl substitution enhances the solubility of ZnPcs, and dextran conjugation conferred water solubility.