Preparation and characterization of hydrocaffeoylchitosan-copper-doxorubicin ternary coordination supermolecule for renal targeting

Hydrocaffeoylchitosan(HCAC)was synthesized and characterized with 15. 6% substitution degree of hydrocaffeic acid. Ternary coordination supermolecule HCAC-Cu-Dox was subsequently fabricated through the solvent-induced precipitation method in the presence of HCAC, Cu(NO₃)₂ ·3H₂O and Dox. The contents of Dox and Cu were(7. 8±0. 3)% and(5. 2±0. 2)% determined by high-performance liquid chromatography(HPLC)and inductively coupled plasma-atomic emission spectrometry(ICP-AES), respectively. The supermolecule was in spherical shape with an average particle size of(68. 7±3. 9)nm observed by TEM. The binding constant of supermolecule was measured, and thermodynamic property was evaluated, indicating that Dox installed in supermolecule existed in amorphous or molecular state. Besides, in vitro release profile indicated that supermolecule possessed satisfactory stable in physiological conditions, and only 13. 5% of Dox were detected in 24 h. Furthermore, the near-infrared fluorescence(NIRF)imaging showed that the supermolecule could be specifically delivered to kidney after intravenous injection, while hardly accumulated in other organs. Cytotoxicity assay by MTT method showed that A498 cells were significantly inhibited after incubation with HCAC-Cu-Dox. In conclusion, HCAC-Cu-Dox ternary coordination supermolecule has potential for renal targeting and treatment.