Chemodynamic nanomaterials for cancer theranostics

Abstract

It is of utmost urgency to achieve effective and safe anticancer treatment with the increasing mortality rate of cancer. Novel anticancer drugs and strategies need to be designed for enhanced therapeutic efficacy. Fenton- and Fenton-like reaction-based chemodynamic therapy (CDT) are new strategies to enhance anticancer efficacy due to their capacity to generate reactive oxygen species (ROS) and oxygen (O₂). On the one hand, the generated ROS can damage the cancer cells directly. On the other hand, the generated O₂ can relieve the hypoxic condition in the tumor microenvironment (TME) which hinders efficient photodynamic therapy, radiotherapy, etc. Therefore, CDT can be used together with many other therapeutic strategies for synergistically enhanced combination therapy. The antitumor applications of Fenton- and Fenton-like reaction-based nanomaterials will be discussed in this review, including: (iþ) producing abundant ROS in-situ to kill cancer cells directly, (ii) enhancing therapeutic efficiency indirectly by Fenton reaction-mediated combination therapy, (iii) diagnosis and monitoring of cancer therapy. These strategies exhibit the potential of CDT-based nanomaterials for efficient cancer therapy.

Keywords: Chemodynamic therapy; Combination therapy; Fenton reaction; Hypoxia; Theranostics.

Scheme 1.

The medical applications of CDT-based nanomaterials and the representative reactions for CDT

Fig. 1

Representative nanomaterials for CDT, including iron-based nanomaterials, organic nanomaterials and other metal-based nanomaterials

Fig. 2

a The scheme of engineered bacteria as a Fenton-like reactor for tumor CDT. Reproduced with permission from Ref. [95]

Fig. 3

Applications of CDT in combination therapy

Fig. 4

a Schematic illustration for nanoreactor preparation, b the cascade reactions in the nanoreactors triggered by tumor acidity at tumor sites, c the chemical structure of TME-responsive PEG-b-P(CPTKMA-co-PEMA), and d the cascade reactions occurring in the nanoreactors. Reproduced with permission from Ref. [134]

Fig. 5

Illustration of NIR light-mediated PDT for enhanced cancer ablation in TME. Reproduced with permission from Ref. [157]

Fig. 6

a Hormone-induced Cu-mediated ROS generation process. b Synergy of checkpoint blockade immunotherapy and nMOF-mediated radical therapy triggered by both hormone and light stimulation. Reproduced with permission from Ref. [214]

Fig. 7

Applications of CDT-based nanomaterials for various imaging modalities