Saccharide Substituted Zinc Phthalocyanines: Optical Properties, Interaction with Bovine Serum Albumin and Near Infrared Fluorescence Imaging for Sentinel Lymph Nodes

Saccharide-substituted zinc phthalocyanines, [2,9(10),16(17),23(24)-tetrakis((1-(β-d-glucose-2-yl)-1H-1,2,3-triazol-4-yl)methoxy)phthalocyaninato]zinc(II) and [2,9(10),16(17),23(24)-tetrakis((1-(β-d-lactose-2-yl)-1H-1,2,3-triazol-4-yl)methoxy)phthalocyaninato]zinc(II), were evaluated as novel near infrared fluorescence agents. Their interaction with bovine serum albumin was investigated by fluorescence and circular dichroism spectroscopy and isothermal titration calorimetry. Near infrared imaging for sentinel lymph nodes in vivo was performed using nude mice as models. Results show that saccharide- substituted zinc phthalocyanines have favourable water solubility, good optical stability and high emission ability in the near infrared region. The interaction of lactose-substituted phthalocyanine with bovine serum albumin displays obvious differences to that of glucose- substituted phthalocyanine. Moreover, lactose-substituted phthalocyanine possesses obvious imaging effects for sentinel lymph nodes in vivo.