硅基纳米探针用于眼部疾病的成像检测与治疗

快速精准的诊断和高效的治疗对于减轻眼部疾病造成的危害至关重要. 在过去的几十年里, 由于具有尺寸小、 比表面积大、 表面易修饰及独特的光/电子/机械性能等优点, 纳米材料已被用于构建不同种类的高性能纳米探针. 其中, 基于其良好的生物相容性, 科学家们已经将硅纳米材料设计为可用于不同眼部疾病诊断与治疗的功能化纳米探针. 本综述主要概述了将硅基纳米探针用于检测和治疗不同眼部疾病(如角膜疾病、 视网膜疾病、 青光眼等)的近期研究进展. 首先, 重点介绍了硅基纳米探针的设计制备及在角膜新生血管、 细菌性角膜炎等角膜疾病的成像检测与治疗中的应用; 然后, 介绍了用于成像检测和治疗视网膜疾病(如色素性视网膜炎和视网膜新生血管)的硅基持续性给药系统的研究成果; 随后, 概述了多功能硅基纳米载药系统的构建及在青光眼治疗领域的应用研究进展; 最后, 简要讨论了将硅基纳米探针用于眼部疾病诊治面临的挑战并对未来的发展前景进行了展望.     

Raman Imaging: An Impending Approach Towards Cancer Diagnosis

In accordance with the recent studies, Raman spectroscopy is well experimented as a highly sensitive analytical and imaging technique in biomedical research, mainly for various disease diagnosis including cancer. In comparison with other imaging modalities, Raman spectroscopy facilitate numerous assistances owing to its low background signal, immense spatial resolution, high chemical specificity, multiplexing capability, excellent photo stability and non-invasive detection capability. In cancer diagnosis Raman imaging intervened as a promising investigative tool to provide molecular level information to differentiate the cancerous vs non-cancerous cells, tissues and even in body fluids. Anciently, spontaneous Raman scattering is very feeble due to its low signal intensity and long acquisition time but new advanced techniques like coherent Raman scattering (CRS) and surface enhanced Raman scattering (SERS) gradually superseded these issues. So, the present review focuses on the recent developments and applications of Raman spectroscopy-based imaging techniques for cancer diagnosis.     

Recent Development of DNA-modified AIEgen Probes for Biomedical Application

A variety of DNA-based probes are utilized for the detections of multiple analytes and DNA nanotechnology has been thriving for recent decades and achieving numerous nanostructures,mainly focusing on DNA morphology modulation and multifunctional systems engineered into to the complicated works.Among the numerous detections,fluorescence method is a non-invasive,highly selective and sensitive means for varieties of applications,but their emissions are often compromised by the aggregation-caused quenching(ACQ)effect,which weakens their applications.The aggregation induced emission luminogens(AIEgens)are created with non emissive or weakly emissive in a low concentration but emit strong fluorescence in a high concentration with aggregated states.Herein,numerous functionalized AIEgens have been emerged and used for detection and imaging and DNA-modified AIEgen probes are introduced.In this vein,here we report the progress on DNA-modified AIEgen probes in recent years and highlight their conjugation strategies including covalent bonding,electrostatic interaction and their applications of biosensing.Moreover,multiple DNA strands are needed to introduce into the DNA-modified AIEgen probes for more purposes.At the end,some challenges are mentioned to discuss the new trend of DNA-modified AIEgen probes.     

Near-infrared dyes,nanomaterials and proteins

Taking the advantage of reduced scattering and low autofluorescence background, the NIR fluorescence probes, such as fluorescence proteins, organic molecules and nanoparticles, not only hold the promise of in vivo imaging of biological processes in physiology and pathology with high signal-to-noise ratio, but also for clinical diagnosis. In this review, we provide an overview of the recent progress on NIR probes, focusing on fundamental mechanisms of NIR dyes and nanoparticles, and protein engineering strategies for NIR proteins.     

成像X射线光电子能谱定量分析研究

探索了直接用实验测得的XPS图像强度来做元素或化学态相对定量分析的可能性。以AgCl和Na2S2O3样品为例，实验结果表明：XPS图像强度与成像时间有良好的线性关系，根据图像强度对两种元素或化学态进行相对定量是可能的。     

Protease sensors for bioimaging

Optical imaging of specific molecular targets and pathways in vivo has recently become possible through continued developments in imaging equipment, reconstruction algorithms, and more importantly the availability of imaging reporter molecules. These reporter molecules encompass photoproteins expressed in vivo and exogenously administered probes detectable by fluorescence and/or bioluminescence imaging. One particularly enticing aspect of optical imaging is the ability to design activatible probes with inherent amplification. This review summarizes our experience in developing novel near-infrared fluorescent (NIRF) imaging agents that report on protease activities. These agents are designed to be biocompatible, highly activatible, and able to produce bright NIRF following protease cleavage.     

Immuno-Desorption Electrospray Ionization Mass Spectrometry Imaging Identifies Functional Macromolecules by Using Microdroplet-Cleavable Mass Tags

We present immunoassay-based desorption electrospray ionization mass spectrometry imaging (immuno-DESI-MSI) to visualize functional macromolecules such as drug targets and cascade signaling factors. A set of boronic acid mass tags (BMTs) were synthesized to label antibodies as MSI probes. The boronic ester bond is employed to cross-link the BMT with the galactosamine-modified antibody. The BMT can be released from its tethered antibody by ultrafast cleavage of the boronic ester bond caused by the acidic condition of sprayed DESI microdroplets containing water. The fluorescent moiety enables the BMT to work in both optical and MS imaging modes. The positively charged quaternary ammonium group enhances the ionization efficiency. The introduction of the boron element also makes mass tags readily identified because of its unique isotope pattern. Immuno-DESI-MSI provides an appealing strategy to spatially map macromolecules beyond what can be observed by conventional DESI-MSI, provided antibodies are available to the targeted molecules of interest.     

Type I Photosensitizer Targeting G-Quadruplex RNA Elicits Augmented Immunity for Cancer Ablation

Type I photodynamic therapy (PDT) represents a promising treatment modality for tumors with intrinsic hypoxia. However, type I photosensitizers (PSs), especially ones with near infrared (NIR) absorption, are limited and their efficacy needs improvement via new targeting tactics. We develop a NIR type I PS by engineering acridinium derived donor-π-acceptor systems. The PS exhibits an exclusive type I PDT mechanism due to effective intersystem crossing and disfavored energy transfer to O₂, and shows selective binding to G-quadruplexes (G4s) via hydrogen bonds identified by a molecular docking study. Moreover, it enables fluorogenic detection of G4s and efficient O₂⋅⁻ production in hypoxic conditions, leading to immunogenic cell death and substantial variations of gene expression in RNA sequencing. Our strategy demonstrates augmented antitumor immunity for effective ablation of immunogenic cold tumor, highlighting its potential of RNA-targeted type I PDT in precision cancer therapy.