Journal of Photochemistry and Photobiology C: Photochemistry Reviews最新文献

The exploration of near-infrared (NIR) emitting materials has been drawing great research interest due to their applications in many fields of technology and medicine. However, such materials usually exhibit low stability and low luminescence quantum yields, so there is still a great demand for the search new emitters that would overcome these limitations. Platinum(II) complexes have the ability to enter into metal-metal interactions, which leads to the formation of new excited states, such as metal-metal-ligand charge transfer (MMLCT), and are very promising NIR materials. It has been observed that the emission properties of Pt(II) complexes can be bathochromically shifted towards the NIR or red region using different approaches. This review summarizes methods for tuning the emission properties of Pt(II) complexes and shifting the emission towards the red and NIR regions of the electromagnetic spectrum.

Controlled drug delivery has profoundly impacted medicine by facilitating precise pharmacotherapy at targeted sites while mitigating adverse effects. Photoresponsive nanocarriers possessing light-mediated conformational changes enable on-demand cargo release with exquisite spatiotemporal precision. This approach enhances delivery efficacy, curtails toxicity, and bolsters patient outcomes. In this paper, we review the physicochemical attributes and applications of organic polymer-based nanoparticles, inorganic nanosystems, photosensitizing agents, and their composite nanomaterials for light-triggered drug delivery, with an emphasis on cancer therapeutics. Current preclinical advances, prospects, limitations, and the tremendous potential of photoresponsive nanomedicines aimed at malignant tumors are discussed through a critical appraisal of contemporary literature. In a nutshell, this review sheds light on an escalating technology poised to illuminate the future of precision drug delivery via localized, controlled release to cancerous tissue.

More than 125 known species of fungi, all part of the Agaricales order, can spontaneously emit light. This bioluminescence results from the oxidation of a luciferin derived from caffeic acid by oxygen under the action of the enzyme luciferase. The production and regeneration of caffeic acid tie together the Krebs cycle and the Shikimic Acid pathway in both fungi and plants. Therefore, successful genetic manipulation of luciferase has led to the development of bioluminescent reporters and eukaryotic organisms that exhibit self-sustained glow. This review aims to discuss the underlying mechanisms of fungal bioluminescence, with a focus on the biochemical and chemical processes that lead to light emission, along with an elaboration on its extensive biotechnological applications.

The increasing number of infectious and chronic diseases, along with the rising healthcare demand caused by an aging population, has led the scientific community to seek novel diagnostic and therapeutic techniques that reduce both mortality rates and healthcare costs. Fluorescence-emission techniques, known for their high sensitivity, rapid response, real-time spatial-temporal resolution, and on-site capabilities, are emerging as key technologies in early diagnosis. However, the biocompatibility of fluorescence probes and their brightness in biological systems continue to be a bottleneck in realizing the full potential of this technique. To address this issue, researchers are turning to efficient luminescence based on through-space conjugation, which is achieved through the clustering of non-conventional chromophores. This review discusses the main recent findings on this phenomenon, analysing its emissive mechanism and how its characteristics can be applied in fields such as sensing, imaging, and various therapies, with a focus on its potential applications in biomedicine.

Photodynamic therapy (PDT) of cancer is a clinically approved, minimally invasive therapeutic approach, combining PDT drug (photosensitizer, PS), molecular oxygen and light to induce cytotoxicity via reactive oxygen species (ROS), which are generated by the light excited PS. Most of the PS molecules fluoresce under excitation with light and fluorescence imaging (FLI) can be employed to evaluate their biodistribution and assess the intratumoral delivery before the therapeutic light application. Light absorption can also be utilized to track a PS by photoacoustic imaging (PAI). However, an excitation of the PS during assessment of its biodistribution through FLI or PAI results in premature photobleaching and causes toxicity. An involvement of a separate fluorescent (luminescent) or photoacoustic imaging probe, which provides imaging contrast in combination with PS without excitation of the latter, can allow for “see-and-treat” approach with FLI/PAI guided PDT. On the other hand, it is well-known that near-infrared (NIR) light is able to penetrate relatively deeper in comparison with visible light, due to reduced absorption and scattering. In addition to the conventional NIR window (NIR-I, ∼700–950 nm), other transparency windows for biological tissues have recently been identified at ∼1000–1700 nm (NIR-II), benefiting optical bioimaging due to the reduced tissue scattering and autofluorescence. Multiple NIR-II imaging probes are currently introduced both for luminescence and photoacoustic bioimaging, providing the significantly improved signal to noise ratio (SNR), imaging depth and resolution. Their combinations with PS are also being increasingly reported, though no review on this hot topic currently exists. Herein, a state-of-the-art in NIR photoluminescence (including fluorescence) and photoacoustic imaging guided PDT is presented. NIR-I and NIR-II spectral ranges are considered, along with both molecular and nanoparticle formulations for imaging guided PDT. It is expected that this review will provide a solid foundation for future translational studies in the domain of NIR imaging guided photodynamic therapy and drug delivery.

Symmetry breaking charge transfer (SBCT) in excited molecules plays a central role in photochemical energy conversion in both artificial and biological systems. The photophysical properties of chromophore aggregates can be tuned over a wide range, which opens up prospects for their application in optoelectronic devices, as well as photosensitizers-catalysts. SBCT occurs at a high rate, so its use at the stage of primary charge separation can be effective in the development of organic photovoltaic devices. The processes of symmetry breaking in quadrupolar and octupolar molecules and symmetrical dimers are analyzed from a unified standpoint. The manifestations of symmetry breaking in the IR and optical spectra are described. The most important experimental results and their theoretical description within simple models are discussed. Particular attention is paid to the physical interpretation of regularities observed in experiments.