Xinyi Zhang

Bio: Xinyi Zhang is an academic researcher from East China University of Science and Technology. The author has contributed to research in topics: Yield (engineering) & Quantum yield. The author has co-authored 1 publications.

Visualizing Aβ deposits in live young AD model mice with a simple red/near-infrared-fluorescent AIEgen

Abstract: Precise and early detection of β-amyloid (Aβ) deposits in situ and in real time is pivotal to the diagnosis and early intervention of Alzheimer’s disease (AD). Optical imaging stands out to be a promising technique for such a task; however, it still remains a big challenge, due to the lack of high-performance imaging contrast agent. Restricted by poor blood-brain barrier (BBB) penetrability, short-wavelength excitation and emission, as well as the aggregation-caused quenching effect, the widely used gold-standard probes cannot be used for early in-vivo imaging of Aβ deposits. Herein, we integrate the Aβ deposits-favored geometry, amphiphilic and zwitterionic molecular structure, extended D-π-A electronic structure, and 3D conformation into one molecule, facilely establishing a simple and economic imaging contrast agent that enjoys high specificity and affinity to Aβ deposits, good BBB penetrability, bright red/near-infrared fluorescence, low interference from autofluorescence, aggregation-induced emission (AIE) feature, high signal-to-noise ratio (SNR), and high contrast. In-vitro, ex-vivo, and in-vivo experiments with different strains of mice indicate that AIE-CNPy-AD holds the universality to Aβ deposits identification. Noteworthily, AIE-CNPy-AD is even able to precisely trace the small and sparsely-distributed Aβ deposits in AD model mice as young as 4-month-old APP/PS1 mice, the youngest having Aβ deposits. Moreover, the present probe could clearly reveal the increase and enlargement of Aβ deposits as the mice grow. Therefore, AIE-CNPy-AD might be an ideal alternative for early AD diagnosis and highly reliable monitoring of AD progression.

Facile Construction of AIE-Active Pyridinyl-Diphenylacrylonitrile Derivatives with Optical Properties Finely-Modulated by the D-A Regulation

Abstract: A series of simply-structured adducts of pyridine and diphenylacrylonitrile, i.e. PyDPACNs, featured with aggregation-induced emission (AIE) characteristics have been designed according to the principle of restriction of the intramolecular motions...

Near-infrared AIEgens with high singlet-oxygen yields for mitochondria-specific imaging and antitumor photodynamic therapy

Abstract: AIE-active photosensitizers (PSs) are promising for antitumor therapy due to their advantages of aggregation-promoted photosensitizing properties and outstanding imaging ability. High singlet-oxygen (1O2) yield, near-infrared (NIR) emission, and organelle specificity are vital parameters to PSs for biomedical applications. Herein, three AIE-active PSs with D–π–A structures are rationally designed to realize efficient 1O2 generation, by reducing the electron–hole distribution overlap, enlarging the difference on the electron-cloud distribution at the HOMO and LUMO, and decreasing the ΔEST. The design principle has been expounded with the aid of time-dependent density functional theory (TD-DFT) calculations and the analysis of electron–hole distributions. The 1O2 quantum yields of AIE-PSs developed here can be up to 6.8 times that of the commercial photosensitizer Rose Bengal under white-light irradiation, thus among the ones with the highest 1O2 quantum yields reported so far. Moreover, the NIR AIE-PSs show mitochondria-targeting capability, low dark cytotoxicity but superb photo-cytotoxicity, and satisfactory biocompatibility. The in vivo experimental results demonstrate good antitumor efficacy for the mouse tumour model. Therefore, the present work will shed light on the development of more high-performance AIE-PSs with high PDT efficiency.

Near-Infrared Aggregation-Induced Emission Luminogens for In Vivo Theranostics of Alzheimer's Disease.

Abstract: Optimized theranostic strategy for Alzheimer's disease (AD) remains almost vacant from bench to clinic. Current probes and drugs attempting to prevent β-amyloid (Aβ) fibrosis encountered failures due to the blood-brain barrier (BBB) penetration challenge and blind intervention time window. Herein, we designed a near-infrared (NIR) aggregation-induced emission (AIE) probe, DNTPH, via balanced hydrophobicity-hydrophilicity. DNTPH binds selectively to Aβ fibrils with a high signal-to-noise ratio. In vivo imaging revealed its excellent BBB permeability and long-term tracking ability with high-performance AD diagnosis. Remarkably, DNTPH exhibited a strong inhibitory effect on Aβ fibrosis and fibril disassembly thereby attenuating Aβ-induced neurotoxicity. DNTPH treatment significantly reduced Aβ plaques and rescued learning deficits in AD mice. Thus, DNTPH serves as the first AIE in vivo theranostic agent for real-time NIR imaging of Aβ plaques and AD therapy simultaneously.

Optical molecular imaging and theranostics in neurological diseases based on aggregation-induced emission luminogens

Abstract: Optical molecular imaging and image-guided theranostics benefit from special and specific imaging agents, for which aggregation-induced emission luminogens (AIEgens) have been regarded as good candidates in many biomedical applications. They display a large Stokes shift, high quantum yield, good biocompatibility, and resistance to photobleaching. Neurological diseases are becoming a substantial burden on individuals and society that affect over 50 million people worldwide. It is urgently needed to explore in more detail the brain structure and function, learn more about pathological processes of neurological diseases, and develop more efficient approaches for theranostics. Many AIEgens have been successfully designed, synthesized, and further applied for molecular imaging and image-guided theranostics in neurological diseases such as cerebrovascular disease, neurodegenerative disease, and brain tumor, which help us understand more about the pathophysiological state of brain through noninvasive optical imaging approaches. Herein, we focus on representative AIEgens investigated on brain vasculature imaging and theranostics in neurological diseases including cerebrovascular disease, neurodegenerative disease, and brain tumor. Considering different imaging modalities and various therapeutic functions, AIEgens have great potential to broaden neurological research and meet urgent needs in clinical practice. It will be inspiring to develop more practical and versatile AIEgens as molecular imaging agents for preclinical and clinical use on neurological diseases.

Development of fluorescent lateral flow immunoassay for SARS-CoV-2-specific IgM and IgG based on aggregation-induced emission carbon dots

Abstract: Understanding the dynamic changes in antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is essential for evaluating the effectiveness of the vaccine and the stage for the recovery of the COVID-19 disease. A rapid and accurate method for the detection of SARS-CoV-2-specific antibodies is still urgently needed. Here, we developed a novel fluorescent lateral flow immunoassay (LFA) platform for the detection of SARS-CoV-2-specific IgM and IgG by the aggregation-induced emission carbon dots conjugated with the SARS-CoV-2 spike protein (SSP). The aggregation-induced emission carbon dots (AIE-CDs) are one of the best prospect fluorescent probe materials for exhibiting high emission efficiency in both aggregate and solid states. The AIE-CDs were synthesized and displayed dual fluorescence emission, which provides a new perspective for the design of a high sensitivity testing system. In this work, the novel LFA platform adopted the AIE carbon dots, which are used to detect SARS-CoV-2-specific IgM and IgG conveniently. Furthermore, this sensor had a low LOD of 100 pg/ml. Therefore, this newly developed strategy has potential applications in the areas of public health for the advancement of clinical research.