Self-Assembly Induced Photosensitization of Long-Tailed Heavy-Atom-Free BODIPY Derivatives for Photodynamic Therapy

Remote Control of Energy Transformation-Based Cancer Imaging and Therapy

Cancer treatment requires precise tumor-specific targeting at specific sites that allows for high-resolution diagnostic imaging and long-term patient-tailorable cancer therapy; while, minimizing side effects largely arising from non-targetability. This can be realized by harnessing exogenous remote stimuli, such as tissue-penetrative ultrasound, magnetic field, light, and radiation, that enable local activation for cancer imaging and therapy in deep tumors. A myriad of nanomedicines can be efficiently activated when the energy of such remote stimuli can be transformed into another type of energy. This review discusses the remote control of energy transformation for targetable, efficient, and long-term cancer imaging and therapy. Such ultrasonic, magnetic, photonic, radiative, and radioactive energy can be transformed into mechanical, thermal, chemical, and radiative energy to enable a variety of cancer imaging and treatment modalities. The current review article describes multimodal energy transformation where a serial cascade or multiple types of energy transformation occur. This review includes not only mechanical, chemical, hyperthermia, and radiation therapy but also emerging thermoelectric, pyroelectric, and piezoelectric therapies for cancer treatment. It also illustrates ultrasound, magnetic resonance, fluorescence, computed tomography, photoluminescence, and photoacoustic imaging-guided cancer therapies. It highlights afterglow imaging that can eliminate autofluorescence for sustained signal emission after the excitation.

NIR-II Light-Driven Genetically Engineered Exosome Nanocatalysts for Efficient Phototherapy against Glioblastoma

Glioblastoma (GBM) poses a significant therapeutic challenge due to its invasive nature and limited drug penetration through the blood-brain barrier (BBB). In response, here we present an innovative biomimetic approach involving the development of genetically engineered exosome nanocatalysts (Mn@Bi2Se3@RGE-Exos) for efficient GBM therapy via improving the BBB penetration and enzyme-like catalytic activities. Interestingly, a photothermally activatable multiple enzyme-like reactivity is observed in such a nanosystem. Upon NIR-II light irradiation, Mn@Bi2Se3@RGE-Exos are capable of converting hydrogen peroxide into hydroxyl radicals, oxygen, and superoxide radicals, providing a peroxidase (POD), oxidase (OXD), and catalase (CAT)-like nanocatalytic cascade. This consequently leads to strong oxidative stresses to damage GBM cells. In vitro, in vivo, and proteomic analysis further reveal the potential of Mn@Bi2Se3@RGE-Exos for the disruption of cellular homeostasis, enhancement of immunological response, and the induction of cancer cell ferroptosis, showcasing a great promise in anticancer efficacy against GBM with a favorable biosafety profile. Overall, the success of this study provides a feasible strategy for future design and clinical study of stimuli-responsive nanocatalytic medicine, especially in the context of challenging brain cancers like GBM.

A type I and type II chemical biology toolbox to overcome the hypoxic tumour microenvironment for photodynamic therapy

Photodynamic therapy (PDT) is a minimally invasive therapeutic modality employed for the treatment of various types of cancers, localized infections, and other diseases. Upon illumination, the photo-excited photosensitizer generates singlet oxygen and other reactive species, thereby inducing cytotoxicity in the target cells. The hypoxic tumour microenvironment (TME), however, poses a limitation on the supply of oxygen in tumour tissues. Moreover, under such conditions, tumour metastasis and drug resistance frequently occur, further compromising the efficacy of PDT in combating tumours. Traditionally, type I photosensitizers with lower oxygen consumption demonstrate significant potential in overcoming hypoxic environments and play a crucial role in determining the therapeutic efficacy of PDT because type I photosensitizers can generate highly cytotoxic free radicals. In comparison, type II photosensitizers exhibit high oxygen dependence. The rate of reactive oxygen species (ROS) generation in the type II process is significantly higher than that in the type I process. Thus, the efficiency and selectivity of PDT depend on the properties of the photosensitizer. Here, the recent development and application of type I and type II photosensitizers, mainly in the past year, are summarized. The design methods, electronic structures, photophysical properties, lipophilic properties, electric charge, and other molecular characteristics of these photosensitizers are discussed in detail. These modifications alter the microstructure of photosensitizers and directly impact the results of PDT. The main content of this paper will have a positive promoting and inspiring effect on the future development of PDT.

Controlled assembly of photosensitizers through directional interactions for effective photooxidation

Despite the fact that effective photosensitizers (PSs) can be achieved through rational molecular design, controlling the hierarchical assemblies of individual PSs with distinct function and morphological nanoscopic architectures remains a challenge. Here, very ordered one-dimensional PS polymers and their hollow tubular structures are presented from aqueous assembly of organic PS-based di- or tri-blocked supramolecules. Di-blocked PSs were interdigitated into 1D fibrils, significantly quenching photooxidation. Meanwhile, tri-blocked PSs were tilted with respect to each other to generate hollow tubules, showing remarkable photo-activities as well as photo-stability, which are particularly suited for green chemistry due to their unusual rapid photo-oxidation.