Heptamethine Cyanine‐Based Nanotheranostics with Catalase‐Like Activity for Synergistic Phototherapy of Cancer

Abstract

Single‐molecule photosensitizers (PSs) for synergistic phototherapy are desirable but highly challenging, due to the competitive relationship between photothermal (PTT) and photodynamic therapy (PDT). Herein, a supramolecular strategy is developed that can tune the stacking pattern of PS molecules in their aggregates to optimize the PTT/PDT efficiency. Specifically, near‐infrared (NIR) heptamethine cyanines (Cy7) are synthesized using tricyanofuran (TCF) as the acceptor and benzothiazole (BTH)/indole (IND) as the donor, where BTH is a less hydrogen‐bonded tecton relative to IND. Both IND‐Cy7‐TCF and BTH‐Cy7‐TCF have similar photophysical properties at the molecular level, but BTH‐Cy7‐TCF in aggregated state exhibits higher singlet oxygen quantum yield (1.3% vs 0.2%) and competitive photothermal conversion efficiency (56.4% vs 62.3%) compared to IND‐Cy7‐TCF, due to the fine‐tuning of hydrogen bonding and intermolecular π–π interactions to form loose molecular stacks. Interestingly, the unique molecular stacking structure provides a binding site and catalytic center for H2O2 that exhibits catalase‐like activity, which can further ameliorate the efficiency of PDT and enhance the synergistic effect of PDT/PTT phototherapy in vitro and in vivo. This study can provide a simple but effective supramolecular strategy to design small molecule PSs with desirable aggregated structure for synergistic dual‐mode phototherapy.

Cyanine-based nanoparticles for near-infrared triggered photothermal therapy against S. aureus

“…Skin tissues surrounding the wounds were evaluated at the 10th day by histological examination [hematoxylin–eosin (H&E) and Masson dyes] to further characterize the wound healing efficacy. 30,38,39 As illustrated in Fig. 4e, H&E staining revealed that the control groups (treated with PBS or NPs only) had insufficient epidermis formation along with infiltrated inflammatory cells.…”

“…Literature reports also showed that cyanine dyes could easily form large aggregates of various morphologies in aqueous solution, and the absorption spectra of these self-assembly systems caused by π–π stacking generally exhibited a blue-shifted absorption peak. 28,30,31 The blue shift phenomenon of the Flav7@DSPE-PEGG NPs was attributed to Flav 7 molecular aggregation due to π–π stacking. After excitation at 808 nm, fluorescence spectra of the Flav7@DSPE-PEGG NPs showed obvious fluorescence bands at 1000–1100 nm (Fig.…”

“…Low dark toxicity was generally the precondition for the safe use of the probe for applications with live recipients. 30 Thus, we first utilized the CCK-8 method to study the cellular toxicity of the Flav7@DSPE-PEGG NPs with L929 as the model cell line and set 1640 culture medium as the negative control. As illustrated in Fig.…”

Self-Assembled Nanoflowers Realizes Synergistic Sterilization with Photothermal and Chemical Kinetics Therapy

“…26 In addition, heptacyanine nanodiagnostics with catalase-like activity can be used for synergistic phototherapy of cancer. 27 From this perspective, the combination of photothermal and chemodynamic therapies is traceable.…”

“…Photothermal therapy (PTT), which involves the use of suitable photothermal agents to convert laser energy into heat, has been well developed due to its noninvasive, remotely controllable, tissue-penetrating specificities, and minimal side-effects. − For example, heavy-atom-structured hypoxia-responsive probes for precise photoacoustic imaging and cancer therapy have been developed . In addition, heptacyanine nanodiagnostics with catalase-like activity can be used for synergistic phototherapy of cancer . From this perspective, the combination of photothermal and chemodynamic therapies is traceable.…”