The direct visualization of micelle transitions is a long‐standing challenge owing to the intractable aggregation‐caused quenching of light emission in the micelle solution. Herein, we report the ...synthesis of a surfactant with a tetraphenylethene (TPE) core and aggregation‐induced emission (AIE) characteristics. The transition processes of surfactant micelles and the microemulsion droplets (MEDs) formed by the surfactant with a TPE core were clearly visualized by a high‐contrast fluorescence imaging method. The fluorescence intensity of the MEDs decreased as the size of MEDs increased as a result of weakening of the restriction of intramolecular rotation (RIR). The results of this study deepen our understanding of micelle‐transition processes and provide solid evidence in favor of the hypothesis that the AIE phenomenon has its origin in the RIR of fluorophores in the aggregate state.
Seeing is believing: The direct visualization of micelle transitions is usually prevented by aggregation‐induced quenching of light emission in the micelle solution. The use of a surfactant with a tetraphenylethene core and aggregation‐induced emission characteristics enabled fluorescence monitoring of the transition of micelles from spherical to rodlike and wormlike structures as the salt concentration of the solution increased (see picture).
The results of numerous studies have led to the development of supramolecular (assembled) organic substances for use in biomedical imaging as part of comprehensive approaches to the diagnosis of ...diseases. This review summarizes recent advances that have been made in the design and fabrication of assembled organic dyes for fluorescence and photoacoustic bioimaging.
The results of numerous studies have led to the development of assembled organic substances for fluorescence and photoacoustic bioimaging as part of comprehensive approaches to the diagnosis of diseases.
Photo-driven theranostics, also known as phototheranostics, relying on the diverse excited-state energy conversions of theranostic agents upon photoexcitation represents a significant branch of ...theranostics, which ingeniously integrate diagnostic imaging and therapeutic interventions into a single formulation. The combined merits of photoexcitation and theranostics endow photo-driven theranostics with numerous superior features. The applications of aggregation-induced emission luminogens (AIEgens), a particular category of fluorophores, in the field of photo-driven theranostics have been intensively studied by virtue of their versatile advantageous merits of favorable biocompatibility, tuneable photophysical properties, unique aggregation-enhanced theranostic (AET) features, ideal AET-favored on-site activation ability and ready construction of one-for-all multimodal theranostics. This review summarised the significant achievements of photo-driven theranostics based on AIEgens, which were detailedly elaborated and classified by their diverse theranostic modalities into three groups: fluorescence imaging-guided photodynamic therapy, photoacoustic imaging-guided photothermal therapy, and multi-modality theranostics. Particularly, the tremendous advantages and individual design strategies of AIEgens in pursuit of high-performance photosensitizing output, high photothermal conversion and multimodal function capability by adjusting the excited-state energy dissipation pathways are emphasized in each section. In addition to highlighting AIEgens as promising templates for modulating energy dissipation in the application of photo-driven theranostics, current challenges and opportunities in this field are also discussed.
This review summarized the progression of AIEgen-based photo-driven theranostics emphasizing on design strategies for efficient photosensitization, photothermal conversion and multimodal functionalities by adjusting the excited energy dissipation.
The development of novel photosensitizing agents with aggregation‐induced emission (AIE) properties has fueled significant advances in the field of photodynamic therapy (PDT). An electroporation ...method was used to prepare tumor‐exocytosed exosome/AIE luminogen (AIEgen) hybrid nanovesicles (DES) that could facilitate efficient tumor penetration. Dexamethasone was then used to normalize vascular function within the tumor microenvironment (TME) to reduce local hypoxia, thereby significantly enhancing the PDT efficacy of DES nanovesicles, and allowing them to effectively inhibit tumor growth. The hybridization of AIEgen and biological tumor‐exocytosed exosomes was achieved for the first time, and combined with PDT approaches by normalizing the intratumoral vasculature as a means of reducing local tissue hypoxia. This work highlights a new approach to the design of AIEgen‐based PDT systems and underscores the potential clinical value of AIEgens.
Hybrid AIEgen and biological tumor‐exocytosed exosome nanovesicles (DES) were combined with photodynamic therapy (PDT) in tumor vessel normalization therapy. DES enhance tumor tissue penetration of AIEgens significantly. Dexamethasone (DEX) was used to normalize vascular function within the tumor microenvironment, thereby reducing local hypoxia and enhancing the PDT effect of DES. Key: aggregation‐induced emission luminogens (AIEgens), photosensitizer (DCPy).
Microbial infectious diseases, especially those caused by new and antibiotic-resistant pathogenic microbes, have become a significant threat to global human health. As an antibiotic-free therapy, ...phototherapy is a promising approach to treat microbial infections due to its spatiotemporal selectivity, non-invasiveness, minimal side effects, and broad antimicrobial spectrum. Although organic photosensitizer-based antimicrobial phototherapy has been extensively studied over the last decade, there has been no specific review article on this topic yet. It is important and timely to summarize recent research progress in this field. This tutorial review highlights the concept and significance of phototherapy and summarizes innovative types of organic photosensitizers with design strategies to deal with microbial infections. In addition, examples of organic antimicrobial photosensitizers, including antibacterial photosensitizers, antiviral photosensitizers, and antifungal photosensitizers are discussed. Finally, current challenges and future directions of organic photosensitizer-based phototherapy for clinical antimicrobial applications are presented. We believe that this tutorial review will provide general guidance for the future development of efficient photosensitizers and encourage preclinical and clinical studies for phototherapy-mediated antimicrobial treatments.
This tutorial review highlights the concept and significance of antibacterial phototherapy. Recent developments, advantages, and challenges of organic photosensitizers in this area are also discussed.
Preparation of non‐conjugated polymers with long‐wavelength emission and high quantum yield (QY) is still a huge challenge. Herein, we report the first example of linear non‐conjugated polyester ...exhibiting yellow–green clusteroluminescence (CL) and a high QY of 38 %. We discovered that the polyester P3 with balanced flexibility and rigidity showed the longest CL wavelength and highest QY. Systematically photophysical characterization unravel the key role of ester cluster in the CL and the cluster formation via the aggregate of ester units was visualized. Moreover, P3 was demonstrated to be a highly selective, quick‐responsive (ca. 1.2 min) and sensitive detector (detection limit is 0.78 μM) for irons owing to the fast disassociation of clusters by irons. This work not only gains further mechanistic insight into CL but also provides a new strategy to design high‐efficiency and long‐wavelength CL, meanwhile, enlightens the glorious application prospect of luminescent polyester.
This work reports the novel example of linear non‐conjugated polyester exhibiting yellow‐green clusteroluminescence and a high quantum yield of 38 %. The formation of ester‐unit cluster is responsible for the emission and is decided by balancing flexible and rigid structures of chains.
The research of purely organic room‐temperature phosphorescence (RTP) materials with stimulus response characteristic has drawn increasing attention for their broad application prospects. However, ...these kinds of materials are really scarce now, especially for those with efficient RTP emissions, which have largely limited their practical applications. Here, an all‐around‐type player in the field of photoinduced phosphorescence material appears, whose RTP efficiency can increase from near 0 to 22% after continuous UV irradiation. Correspondingly, the UV‐written patterns based on them can be clearly observed by the naked eye in daytime or even under sunlight. Moreover, these materials are found to show excellent photostability, and the strong RTP emission can still be observed after repeated activation for more than 50 times. The high RTP efficiency and good photostability make these photoinduced RTP materials exhibit an attractive prospect for potential applications in many fields, including leak test, microcrack detection, programmable information storage, and encryption.
An all‐around‐type player in the field of photoinduced phosphorescence material is presented, whose room‐temperature phosphorescence (RTP) efficiency can increase from near 0% to 22% after continuous UV irradiation. The high RTP efficiency and good photostability make these materials exhibit an attractive prospect for potential applications in many fields, including leak tests, microcrack detection, programmable information storage, and encryption.
Aggregate materials have attracted tremendous attention because of their modified or totally different properties compared with their molecular counterparts. Among various mesoscopic aggregate ...materials, polymeric micromaterials possess the advantages of diverse structures and flexible manufacturing, enabling them to serve as excellent carriers for aggregation‐induced emission luminogens (AIEgens) and good platforms for the research of aggregate science. In recent years, polymeric micromaterials constructed from AIEgens have witnessed rapid development and show great application potential in various fields, such as environmental sensing, multicolor displaying, and energy conversion. This review summarizes the recent progress on the design, preparation, structure, and applications of AIEgen‐based polymeric micromaterials. According to the structure features, AIEgen‐based polymeric micromaterials are divided into three categories, including microsphere, microfiber, and other‐shaped microparticles. The most representative examples in each category are highlighted by focusing on their subdivision structures such as solid microsphere, porous microsphere, microcapsule, microfiber doped‐ or coated with AIEgens, and core–shell microfiber. Finally, the challenges and prospects in this research field are also discussed. It is hoped that this review can provide readers with an overall view on the development of AIEgen‐based polymeric micromaterials and boost their further research.
This review summarizes recent advances and implementation of functional polymeric micromaterials based on aggregation‐induced emission luminogens (AIEgens). Diverse typical AIEgen‐based polymeric micromaterials, including microsphere, microfiber, and other shaped microparticles, are carefully discussed. Current challenges and future perspectives for the development of AIEgen‐based polymeric micromaterials are pointed out at the end.
The severe hypoxia in solid tumors and the vicious aggregation‐caused fluorescence quenching (ACQ) of conventional photosensitizers (PSs) have limited the application of fluorescence imaging‐guided ...photodynamic therapy (PDT), although this therapy has obvious advantages in terms of its precise spatial–temporal control and noninvasive character. PSs featuring type I reactive oxygen species (ROS) based on free radicals and novel aggregation‐induced emission (AIE) characteristics (AIE‐PSs) could offer valuable opportunities to resolve the above problems, but molecular engineering methods are rare in previous reports. Herein, a strategy is proposed for generating stronger intramolecular charge transfer in electron‐rich anion‐π+ AIE‐active luminogens (AIEgens) to help suppress nonradiative internal conversion and to promote radiative and intersystem crossing to boost free radical generation. Systematic and detailed experimental and theoretical calculations prove the proposal herein: the electron‐donating abilities are enhanced in collaborative donors, and the AIE‐PSs exhibit higher performance in near‐infrared fluorescence imaging‐guided cancer PDT in vitro/vivo. This work serves as an important reference for the design of AIE‐active free radical generators to overcome the ACQ and tumor hypoxia challenges in PDT.
A feasible molecular engineering method is proposed for achieving the transformation of AIE‐active type I free radical ROS generators from type II 1O2 species to overcome ACQ effect and enable high‐performance photodynamic theory under hypoxia.
Since the introduction of the concept of aggregation-induced emission (AIE) in 2001, many research groups have become involved in AIE research. Aggregation-induced emission luminogens (AIEgens) have ...emerged as a novel type of advanced material with excellent performance in various fields. Much effort has been devoted to determining the AIE mechanism(s) by theoreticians and experimentalists. Restriction of intramolecular motion has been recognized as the general working mechanism of AIE, but the mechanims of some AIE systems still remain unclear. In this focus article, the progress of the fundamental understanding of the AIE mechanism is reviewed and the future developments in AIE research are discussed. The goal is to provide a brief yet insightful introduction and interpretation of the subject to both new and experienced AIE researchers.
In-depth discussion on recent progress of fundamental understanding of AIE mechanisms, identifying the existing challenges and opportunities for future developments.
