An optical fan was demonstrated to screen leukemia cells from the blood sample at the single‐cell level in a noninvasive and noncontact manner. Further details can be found in the article by Xiaoshuai Liu, Yuchao Li, Xiaohao Xu, Yao Zhang, Baojun Li ( e201900155 ).
A false‐colored and merged image of fresh, ex vivo rat kidney acquired using an excitation‐scanning hyperspectral imaging system. The spectral image was acquired using excitation wavelengths from 360 to 550 nm. Colors represent principal components extracted from a spectral image cube featuring no added labels or markers. Further details can be found in the article by Peter F. Favreau, Joshua A. Deal, Bradley Harris, et al. ( e201900183 ).
A multi‐wavelength Spatial Frequency Domain Imaging (SFDI) utilizes structured illumination to provide absorption and reduced scattering coefficient maps of colorectal tissue. Combining SFDI with a Machine Learning algorithm ‐ AdaBoost, different types of colorectal tissues including normal, adenomatous polyp and cancer, can be differentiated with high accuracy. This new technique provides a potential method to assist in colorectal cancer screening. Further details can be found in the article by Shuying Li, Yifeng Zeng, William C. Chapman Jr, et al. ( e201960241 ).
Transcranial photobiomodulation (tPBM) with wavelength at 808 nm was applied to a rat model of acute seizures. The tPBM successfully attenuated convulsive status epilepticus, and the tPBM was shown to reduce the apoptosis of parvalbumin‐positive interneurons (PV‐INs) and preserved the integrity of perisomatic inhibitory network of PV‐INs to principle cells in the hippocampus. Further details can be found in the article by Chung‐Min Tsai, Shwu‐Fen Chang, and Hsi Chang ( e202000095 ).
Intraoperative neurosurgical diagnosis of brain tumor determines the success rate of patients' prognoses. We firstly proposed a novel approach based on an optical method to distinguish the site of the tumor functionally. The promoted technique is non‐invasive, non‐radioactive, dye‐free, and potential of real‐time monitoring, which is still not available nowadays by using other techniques. The method could be applied to neuroimage guiding system for precision surgery of brain. Further details can be found in the article by Xin‐Rui Liu, Tien‐Yu Hsiao, Yun‐Qian, et al. ( e201900200 ).
The figure shows the detailed morphology of vasculature and dynamic changes of the blood vessel diameter and density and the oxygen saturation in the blood vessels in fetal brain after acute prenatal ethanol exposure in the second‐trimester equivalent murine model obtained using a real‐time photoacoustic tomography (PAT) system. Further details can be found in the article by Tianqi Shan, Yuan Zhao, Shixie Jiang, Huabei Jiang ( e201960161 ).
This work addresses an unmet clinical need, that of glaucoma monitoring through intraocular pressure (IOP) interrogation in patients with artificial corneas (keratoprost hesis). We demonstrate direct integration of a low‐drift, fiber‐optic Fabry‐Perot pressure sensor embedded in the keratoprosthesis via rapid, non‐contact micromagnetic fiber alignment. IOP interrogation is achieved by using white‐light interferometry, which provides sub‐mmHg IOP sensitivity. Further details can be found in the article by Pui‐Chuen Hui, Katia Shtyrkova, Chengxin Zhou, et al. ( e202000031 ).
Top: Illustration of how to obtain 3D embryo images from a locust egg using OCT B‐scans. The internal structures of the embryo can be clearly identified as it develops. Bottom: The real time observation of katatrepsis and twist of a lowland locust embryo on days 7‐8, as the embryo develops. The embryonic movements can be readily identified by tracking the positions of the embryo's eyes (E1 and E2). Further details can be found in the article by Ya Su, Liya Wei, Hao Tan, et al. ( e201960047 ).
A dual‐raster‐scanned photoacoustic microscope (DRS‐PAM) was reported, which integrates a two‐dimensional motorized translation stage for large field‐of‐view imaging and a two‐axis fast galvanometer scanner for real‐time imaging. The DRS‐PAM provides a flexible transition from wide‐field monitoring the vasculature of organs to real‐time imaging of local dynamics. Further details can be found in the article by Fei Yang, Zhiyang Wang, Wuyu Zhang, et al. ( e202000022 ).
iSERS (SERS=surface‐enhanced Raman scattering) microscopy is an emerging Raman‐based staining technique for the selective localization of target proteins on cells and tissues using antibody‐ SERS nanotag conjugates. In this contribution we demonstrate the feasibility of iSERS for imaging of programmed cell death‐ligand 1 (PD‐L1), an important predictive biomarker, on single SkBr‐3 breast cancer cells. Further details can be found in the article by Elzbieta Stepula, Matthias König, Xin‐Ping Wang, et al. ( e201960034 ).
The detection of colon cancer by using Poincaré sphere and 2D polarimetric imaging approach. Further details can be found in the article by Deyan Ivanov, Viktor Dremin, Alexander Bykov, Ekaterina Borisova, et al. ( e202000082 ).
A comparative analysis of intrinsic skin aging between Caucasian and Asian subjects by slide‐free in vivo harmonic generation microscopy is reported. The cellular and nuclear areas of basal cells in Caucasians and Asians are found to increase at the same rate, ideal for scoring age. On the other hand, the viable epidermis thickness, the dermal papilla volume and height in Caucasians are found to decrease faster than those in Asians. Further details can be found in the article by Kuan‐Hung Lin, Yi‐Hua Liao, Ming‐Liang Wei, and Chi‐Kuang Sun ( e201960063 ).
Infrared spectroscopy enables insight into light‐activated riboflavin‐induced collagen cross‐linking for future intervertebral disc treatment and repair. Further details can be found in the article by Ioannis Vasilikos, Julian Haas, Graciosa Q. Teixeira, Julia Nothelfer, Cornelia Neidlinger‐Wilke, Hans‐Joachim Wilke, Andreas Seitz, Demetrios G. Vavvas, Josef Zentner, Jürgen Beck, Ulrich Hubbe, and Boris Mizaikoff ( e202000110 ).
Successful therapy of twin‐to‐twin transfusion syndrome requires accurate imaging to guide laser photocoagulation of the anastomosing placental vessels. Photoacoustic (PA) imaging is an alternative imaging method that provides contrast for hemoglobin, and in this study, it was used to visualize chorionic superficial and subsurface vasculature in human placentas. The strong potential of PA imaging to guide minimally invasive fetal therapies was demonstrated. Further details can be found in the article by Efthymios Maneas, Rosalind Aughwane, Nam Huynh, et al. ( e201900167 ).
A new high‐speed cellular imaging method using clinically applicable moxifloxacin labeling, called as moxifloxacin based confocal microscopy (MBCM), was developed for fast and sensitive tumor detection and delineation. The MBCM demarcated malignant brain tumor from normal brain by visualizing dense and irregular cell distribution in the tumor. An image processing algorithm was developed for automated brain tumor detection. Further details can be found in the article by Seunghun Lee, Won Yeong Park, Hoonchul Chang, et al. ( e201900197 ).
This study proposed a Sparse‐Graph Manifold Learning (SGML) method to balance the sparseness and morphology preserving for bioluminescence tomography reconstruction. It inherits the benefits of non‐convex sparsity constraint and dynamic Laplacian graph model. The results of numerical simulations and in vivo experiments demonstrate that the proposed method yields accurate and robust results in terms of tumor spatial location and morphology recovery. Further details can be found in the article by Hongbo Guo, Ling Gao, Jingjing Yu, et al. ( e201960218 )
The first post-pandemic face-to-face international conference in Biophotonics took place in Porto in April 2022. High quality and inspiring presentations have been delivered by leading scientists and internationally recognized professionals, standing on the forefront of Biophotonics research and representing broadness of the field. A selected number of these presentations resulted in the papers that are presented in this special issue. The cover images were selected from Hoffer et al., Lomanovskaya et al., Li et al., and Burton et al. (clockwise).
Immunofluorescence image of Plasmodium berghei sporozoites (red) in HeLa cells 1.5 hours post infection. The parasitophorous vacuole membrane (PVM) that surrounds the parasites was stained with antibodies against the PVM‐resident protein UIS4 (grey). DNA was stained with DAPI (blue). Imaging was performed on a Leica SP8 confocal microscope. For further details, readers are referred to the article by Bindschedler et al. on p. e13271 of this issue.
A large‐depth‐of‐field full‐field optical angiography (LD‐FFOA) method is developed to expand the depth‐of‐field (DOF). The contrast pyramid fusion algorithm is used to fuse 10 FFOA images at different focus depth. Cover images of mouse ear shows LD‐FFOA image has higher contrast and more detailed features. The LD‐FFOA method solves the defocused problem caused by the limited DOF of lens, the curved surface and uneven thickness of the sample. Further details can be found in the article by Mingyi Wang, Nanshou Wu, Hongheng Huang, et al. ( e201800329 ).
This study presents a novel intraoperative in vivo imaging approach which harnessed Cerenkov luminescence (CL) to detect primary and metastatic colorectal cancer (CRC) using clinically approved radiopharmaceuticals. In the mice and swine experiments, the proposed approach effectively improved the effect of CRC surgery. The approach is believed to be promising for utilizing CL in open surgery. Further details can be found in the article by Zeyu Zhang, Yawei Qu, Yu Cao et al. ( e201960152 )
