A Carbon Quantum Dot-Derived Platform Combining Photothermal and ¹³¹I Radionuclide Oncotherapy

It is imperative to optimize the therapeutic efficacy of anticancer medicine for translation from preclinical investigation to clinical practice. Typically, a single antitumor protocol usually cannot suppress tumor growth efficiently while sparing the side effects on normal organs or tissues. Here, we proposed a strategy combining radiopharmaceutical with photothermal therapy, which involved the construction of ¹³¹I-radiolabeled carbon quantum dots (¹³¹I-CQDs) with high photoactivity. The designed CQDs were well prepared and characterized, of which the photothermal capacity was demonstrated through a comprehensive evaluation in vitro and in vivo. More interestingly, ¹³¹I, a pivotal therapeutic radionuclide in biomedicine, can be conjugated with CQDs with high radiochemical yield, and the prepared ¹³¹I-CQDs can keep approximately 75% radiochemical encapsulation in different physiological media after a week. ¹³¹I-CQDs exhibit high cancer cell binding affinity, good endocytosis, and low efflux on 4T1 cells, demonstrating enhanced therapeutic effects in cell viability assays. In animal models, ¹³¹I-CQDs have manifested synergistic anticancer potential from radionuclide and photothermal therapy, capable of impeding cancer growth and prolonging survival of murine tumor-bearing models. The outcomes of this study suggest that CQD-derived platforms can combine photothermal and ¹³¹I radionuclide oncotherapy, providing an alternative avenue to promoting the application of nanoscale materials in anticancer fields.