Congratulations to Kaikai Wen's article published in Angewandte Chemie International Edition

Compared with traditional cancer treatment methods, photothermal therapy and photodynamic therapy have attracted great interest from researchers due to their non-invasiveness, effectiveness and less side effects. Photothermal therapy (PTT) can utilize photothermal nanoagents However, high temperature can lead to overexpression of heat shock proteins, resulting in incomplete apoptosis of cancer cells and tumor recurrence, thereby weakening the PTT effect. On the other hand, photodynamic therapy (PDT) can produce highly toxic Singlet oxygen (1O2), thereby killing cancer cells. It is well known that tumors have different physiological environments. In normoxic tumor sites, 1O2 can destroy cells and blood vessels to destroy tumors, therefore, it has moderate photothermal effects and strong light Dynamically acting nanoagents may be the best option for killing cells and blood vessels at these sites. On the other hand, a hypoxic microenvironment is formed inside dense tumors, which limits the effect of PDT, and when PDT is used in combination with PTT, Hyperthermia can increase the oxygen content in microvessels inside dense tumors, therefore, phototherapy nanoplatforms with strong photothermal and photodynamic effects may be the best solution to eliminate cancer cells inside hypoxic dense tumors. The photothermal and photodynamic effects of materials can be precisely regulated to achieve precise tumor treatment.

  In the previous work, the team of Professor Huang Hui obtained a series of organic semiconductor nanoparticles with strong photothermal and photodynamic effects through molecular design, using the strategy of heavy atom effect and the combination of D-A structure and twisted conformation respectively. Murine tumors have a good therapeutic effect (Small, 2020, 10.1002/smll.202000909; ACS Appl. Mater. Interfaces, 2019, 19, 17884-17893.).

Figure 1(A) Schematic diagram of the preparation of PPy-Te NPs. (B–E) Full spectrum of NPs IV after etching and XPS spectra of C 1s, N 1s, Te 3d electrons. (F) UV-Vis-NIR absorption spectra of NPs I, NPs VII, NPs IV and PPT NPs (the concentration of NPs was 100 μg mL-1). (G) Size of NPs I-VII measured by DLS. (H) TEM image of NPs Scale bar, 200 nm. (I) Zeta potential of NPs I-VII measured by DLS. (J) UV-Vis-NIR absorption spectra of NP II-VII (100 μg mL-1).

In order to further realize the precise control of photothermal and photodynamic effects, the research team led by Professor Huang Hui synthesized a series of copolymer nanoparticles with different ratios of pyrrole and telluride in situ through controlled oxidative copolymerization. The realization of the in situ copolymerization of telluride and pyrrole was confirmed by X-ray photoelectron spectroscopy and ultraviolet-visible-near-infrared spectroscopy. Further systematic study found that with the increase of the ratio of pyrrole, the photothermal conversion efficiency increased sequentially, and with the increase of the ratio of telluride, the yield of reactive oxygen species increased. Therefore, by changing the molar ratio of pyrrole to telluride, the photothermal and photodynamic effects of semiconductor nanoagents under laser irradiation in the near-infrared region can be precisely and systematically tuned. Animal experiments show that this type of nanoparticles has an efficient therapeutic effect on tumors and has good biocompatibility. Therefore, this work proposes a simple method to tune the photothermal and photodynamic effects of organic semiconductor nanoparticles, which can be successfully applied in tumor therapy.

Fig. 2(A) Temperature curve of NPs II-VII (100 μg mL-1) and HO. (B) Infrared thermal image of NPs II-VII at the highest temperature and PCE of NPs II-VII calculated from Fig. 2A. (C) Fitted line between pyrrole content and PCE, reactive oxygen species (ROS) yield in NPs II-VII. (D) Temperature curve of NPs IV irradiation for five cycles (100 μg mL-1).

Relevant research results, with the theme of "Precisely Tuning Photothermal and Photodynamic Effects of Polymeric Nanoparticles by Controlled Copolymerization", were published in the famous journal "Angewandte Chemie International Edition" (Angew. Chem. Int. Ed. ) in the field of chemical materials (DOI: 10.1002/ anie.202004181). The first author of the paper is Wen Kaikai, a doctoral student at the School of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences. The co-first author is Wu Lifen, a master student from Southwest University of Science and Technology. The corresponding authors are Professor Huang Hui and Professor Duan Tao of Southwest University of Science and Technology. In addition, this work was also strongly supported by Professor Ma Han from the Fifth Affiliated Hospital of Sun Yat-Sen University in animal experiments.