Metal-based
photothermal therapy has been widely used in the biomedicine field and includes
gold nanoparticles,
silver nanoparticles and
copper sulfide nanoparticles. Furthermore, the coordination bonding-based
metal nanocomplex is a new generation of photothermal agents for
cancer therapy due to its high photothermal transduction efficiency, good biocompatibility, biodegradation and bioactivity. In this study, we designed a coordination bonding-based
copper (Cu(II))-carboxylate ternary architecture, which consists of a conjugate
dopamine-modified nontoxic
hyaluronic acid,
copper ions and
citric acid. When the Cu(II) coordinated with the carboxyl groups, the splitting d orbitals energy gap of Cu(II) and the capability of electron transition were enhanced, which can increase the extinction ability in the near-infrared region for enhancing
photothermal therapy. Moreover, the degradation of
hyaluronic acid by
hyaluronidase highly expressed in the tumor microenvironment led to the release of Cu-
citric acid complexes, thus exhibiting an additional chemotherapeutic effect. The nanocomplexes possessed high-performance photothermal conversion, determined to be 21.3%. The
solution could be easily heated to above 42 °C, which was sufficient to ablate the
cancer cells. An obvious decrease in cell viability was observed in B16F10 cells incubated with the nanocomplexes under
laser at the lower concentration of 20 μg/mL Cu(II). Upon near-infrared
laser irradiation, the nanocomplexes showed high
photothermal therapy and chemotherapeutic efficacy for
breast cancer in vivo. This study demonstrated that the Cu(II)-carboxylate coordination nanocomplex is a promising new effective and facilely prepared thermochemotherapy agent for combination
therapy against
cancer.