癌症是人类生命的一大威胁，而肿瘤的侵袭和转移是癌症患者死亡的主要原因之一。在这一复杂过程中，循环肿瘤细胞（CTC）等血液循环中的粒子起到十分关键的作用，所以监测血液循环中的CTC和其他肿瘤相关的粒子可以促进肿瘤转移的研究。光学活体流式细胞仪（IVFC）是一种基于激光的新兴技术，可在体内无创监测循环细胞，包括CTC等肿瘤相关的颗粒。这一强大的工具已被广泛应用于癌症相关的多个领域，尤其是肿瘤转移研究。因此，总结分析IVFC在肿瘤转移研究中的应用具有重要意义。本文介绍IVFC的检测原理，总结基于荧光发光、光声效应、计算机视觉等光学技术的荧光活体流式细胞仪、光声活体流式细胞仪、图像活体流式细胞仪等IVFC分类，对IVFC应用于肝癌、前列腺癌、乳腺癌、黑色素瘤等肿瘤转移的相关研究进行综述，并总结和展望IVFC对肿瘤转移研究的应用。

The study of circulating cells in the blood stream is critical, as it covers many fields of biomedicine, including immunology, cell biology, oncology, and reproductive medicine. In-vivo flow cytometry (IVFC) is a new tool to monitor and count cells in real time for long durations in their native biological environment. This review describes two main categories of IVFC, i.e., labeled and label-free IVFC. It focuses on label-free IVFC and introduces its technological development and related biological applications. Because cell recognition is the basis of flow cytometry counting, this review also describes various methods for the classification of unlabeled cells, including the latest machine learning-based technologies.

The skin is the largest organ in humans. It comprises about 16% of our body. Many diseases originate from the skin, including acne vulgaris, skin cancer, fungal skin disease, etc. As a common skin cancer in China, melanoma alone grows at year rate of nearly 4%. Therefore, it is crucial to develop an objective, reliable, accurate, non-invasive, and easy-to-use diagnostic method for skin diseases to support clinical decision-making. Raman spectroscopy is a highly specific imaging technique, which is sensitive, even to the single-cell level in skin diagnosis. Raman spectroscopy provides a pattern of signals with narrow bandwidths, making it a common and essential tool for researching individual characteristics of skin cells. Raman spectroscopy already has a number of clinical applications, including in thyroid, cervical and colorectal cancer. This review will introduce the advantages and recent developments in Raman spectroscopy, before focusing on the advances in skin diagnosis, including the advantages, methods, results, analysis, and notifications. Finally, we discuss the current limitations and future progress of Raman spectroscopy in the context of skin diagnosis.

We propose a novel retinal layer segmentation method to accurately segment 10 retinal layers in optical coherence tomography (OCT) images with intraretinal fluid. The method used a fan filter to enhance the linear information pertaining to retinal boundaries in an OCT image by reducing the effect of vessel shadows and fluid regions. A random forest classifier was employed to predict the location of the boundaries. Two novel methods of boundary redirection (SR) and similarity correction (SC) were combined to carry out boundary tracking and thereby accurately locate retinal layer boundaries. Experiments were performed on healthy controls and subjects with diabetic macular edema (DME). The proposed method required an average of 415 s for healthy controls and of 482 s for subjects with DME and achieved high accuracy for both groups of subjects. The proposed method requires a shorter running time than previous methods and also provides high accuracy. Thus, the proposed method may be a better choice for small training datasets.

光动力疗法是一种利用特定波长的光激发光敏剂产生活性氧，进而杀死肿瘤细胞或者病变组织的方法。近年来，光动力疗法以其非侵入性、副作用小等优点受到了国内外的广泛关注，但该方法的应用却受到了激发光穿透深度及光敏剂亚细胞靶向能力的限制。本研究团队合成、表征了具有核仁靶向能力的碳点光敏剂，并将其用于细胞双光子光动力疗法，在低剂量的光照和光敏剂条件下，获得了优异的治疗效果。

Photodynamic therapy (PDT) takes advantage of photosensitizers (PSs) to generate reactive oxygen species (ROS) for cell killing when excited by light. It has been widely used in clinic for therapy of multiple cancers. Currently, all the FDA-approved PSs, including porphyrin, are all small organic molecules, suffering from aggregation-caused quenching (ACQ) issues in biological environment and lacking tumor targeting capability. Nanoparticles (NPs) with size between 20 nm and 200 nm possess tumor targeting capability due to the enhanced permeability and retention (EPR) effect. It is urgent to develop a new strategy to form clinical-approved-PSs-based NPs with improved ROS generation capability. In this study, we report a strategy to overwhelm the ACQ of porphyrin by doping it with a type of aggregation-induced emission (AIE) luminogen to produce a binary NPs with high biocompatibility, and enhanced fluorescence and ROS generation capability. Such NPs can be readily synthesized by mixing a porphyrin derivative, Ce6 with a typical AIE luminogen, TPE-Br. Here, our experimental results have demonstrated the feasibility and effectiveness of this strategy, endowing it a great potential in clinical applications.

The fluorescence-based in vivo flow cytometry (IVFC) is an emerging tool to monitor circulating cells in vivo. As a noninvasive and real-time diagnostic technology, the fluorescence-based IVFC allows long-term monitoring of circulating cells without changing their native biological environment. It has been applied for various biological applications (e.g., monitoring circulating tumor cells). In this work, we will review our recent works on fluorescence-based IVFC. The operation principle and typical biological applications will be introduced. In addition, the recent advances in IVFC flow cytometry based on photoacoustic effects and other label-free detection methods such as imaging-based methods, diffuse-light methods, hybrid multimodality methods and multispectral methods are also summarized.