Conclusion
Our results suggest that well-designed AIE nanodots are promising for image-guided PDT applications.
Methods
The TPETS nanodots were prepared by nano-precipitation method and further conjugated with thiolated cRGD (cRGD-SH) through a click reaction to yield the targeted TPETS nanodots (T-TPETS nanodots). Nanodots were characterized for encapsulation efficiency, conjugation rate, particle size, absorption and emission spectra and ROS production. The targeted fluorescence imaging and antitumor efficacy of T-TPETS nanodot were evaluated both in vitro and in vivo. The mechanism of cell apoptosis induced by T-TPETS nanodot mediated-PDT was explored. The biocompatibility and toxicity of the nanodots was examined using cytotoxicity test, hemolysis assay, blood biochemistry test and histological staining.
Results
The obtained nanodots show bright red fluorescence and highly effective 1O2 generation in aggregate state. Both in vitro and in vivo experiments demonstrate that the nanodots exhibit excellent tumor-targeted imaging performance, which facilitates image-guided PDT for tumor ablation in a hepatocellular carcinoma model. Detailed analysis reveals that the nanodot-mediated PDT is able to induce time- and concentration-dependent cell death. The use of PDT at a high PDT intensity leads to direct cell necrosis, while cell apoptosis via the mitochondria-mediated pathway is achieved under low PDT intensity.