Near infrared and pH dual-activated coordination polymer nanosystem for imaging-guided chemo-photothermal therapy

Abstract

As the effective photothermal agent, NIR cyanine dye has shown great promise in cancer therapy due to its distinct NIR absorbance and excellent thermal conversion superiority. Up to date, various nanosystems have been developed as the delivery carrier for NIR dye in order to overcome the inherent issues such as poor stability, low bioavailability and insufficient therapy efficacy. However, the huge obstacle of current nanocarriers for NIR dye encapsulation frequently lies in high leakage risk, complicated preparation and poor biocompatibility, which significantly hinder their further application in cancer therapy. To make up for these deficiencies, we developed a facile and universal strategy to fabricate a novel nanoscale coordination polymers (NCPs) through the co-coordination driven assembly of cypate and carboxyl ligand with Gd3+. Through this design, cypate can be effectively introduced into the interior of NCPs through the coordination between its carboxyl group and Gd3+, resulting in the enhanced stability, reduced leakage risk, and improved therapeutic efficacy. The fabricated NCPs have exhibited multimodal imaging guided tumor targeting chemo-photothermal property. After accumulation in tumor site, rapid drug release can be effectively triggered by NIR laser induced hyperthermia and acidic endo/lysosomal microenvironment, which fundamentally improved the synergistic chemo-photothermal efficacy for tumor killing. The newly fabricated NCP system can exert distinctively chemo-photothermal synergistic efficacy for cancer therapy and will pave a new avenue for the application of NCPs in biomedical field.