A versatile, automated and high-throughput drug screening platform for zebrafish embryos

Zebrafish provide a unique opportunity for drug screening in living animals, with the fast developing, transparent embryos allowing for relatively high-throughput, microscopy-based screens. However, the limited availability of rapid, flexible imaging and analysis platforms has limited the use of zebrafish in drug screens. We have developed an easy-to-use, customisable automated screening procedure suitable for high-throughput phenotype-based screens of live zebrafish. We utilised the WiScan® Hermes High Content Imaging System to rapidly acquire brightfield and fluorescent images of embryos, and the WiSoft® Athena Zebrafish Application for analysis, which harnesses an Artificial Intelligence-driven algorithm to automatically detect fish in brightfield images, identify anatomical structures, partition the animal into regions, and exclusively select the desired side-oriented fish. Our initial validation combined structural analysis with fluorescence images to enumerate GFP-tagged haematopoietic stem and progenitor cells in the tails of embryos, which correlated with manual counts. We further validated this system to assess the effects of genetic mutations and x-ray irradiation in high content using a wide range of assays. Further, we performed simultaneous analysis of multiple cell types using dual fluorophores in high throughput. In summary, we demonstrate a broadly applicable and rapidly customisable platform for high-content screening in zebrafish.

Longitudinal high-resolution imaging through a flexible intravital imaging window

Intravital microscopy (IVM) is a powerful technique that enables imaging of internal tissues at (sub)cellular resolutions in living animals. Here, we present a silicone-based imaging window consisting of a fully flexible, suture-less design that is ideally suited for long-term, longitudinal IVM of growing tissues and tumors. Crucially, we show that this window, without any customization, is suitable for numerous anatomical locations in mice using a rapid and standardized implantation procedure. This low-cost device represents a substantial technological and performance advance that facilitates intravital imaging in diverse contexts in higher organisms, opening new avenues for in vivo imaging of soft and fragile tissues.One-sentence summaryThis study presents a versatile, fully flexible imaging window that acts as an implantable transparent ‘second skin’ for small laboratory animal in vivo imaging.

A versatile automated high-throughput drug screening platform for zebrafish embryos

Zebrafish provide a unique opportunity for drug screening in living animals, with the fast developing, transparent embryos allowing for relatively high throughput, microscopy-based screens. However, the limited availability of rapid, flexible imaging and analysis platforms has limited the use of zebrafish in drug screens. We have developed a easy-to-use, customisable automated screening procedure suitable for high-throughput phenotype-based screens of live zebrafish. We utilised the WiScan®Hermes High Content Imaging System to rapidly acquire brightfield and fluorescent images of embryos, and the WiSoft®Athena Zebrafish Application for analysis, which harnesses an Artificial Intelligence-driven algorithm to automatically detect fish in brightfield images, identify anatomical structures, partition the animal into regions, and exclusively select the desired side-oriented fish. Our initial validation combined structural analysis with fluorescence images to enumerate GFP-tagged haematopoietic stem and progenitor cells in the tails of embryos, which correlated with manual counts. We further validated this system to assess the effects of genetic mutations and x-ray irradiation in high content using a wide range of assays. Further, we performed simultaneous analysis of multiple cell types using dual fluorophores in high throughput. In summary, we demonstrate a broadly applicable and rapidly customisable platform for high content screening in zebrafish.

Mesoporous Silica Nanoparticles in Bioimaging

A biomedical contrast agent serves to enhance the visualisation of a specific (potentially targeted) physiological region. In recent years, mesoporous silica nanoparticles (MSNs) have developed as a flexible imaging platform of tuneable size/morphology, abundant surface chemistry, biocompatibility and otherwise useful physiochemical properties. This review discusses MSN structural types and synthetic strategies, as well as methods for surface functionalisation. Recent applications in biomedical imaging are then discussed, with a specific emphasis on magnetic resonance and optical modes together with utility in multimodal imaging.

Comparison between a new ultrasound probe with a capacitive micromachined transducer (CMUT) and a traditional one in musculoskeletal pathology

Background The capacitive micromachined ultrasound transducer (CMUT) is a new ultrasound (US) probe manufactured by state-of-the-art cutting-edge semi-conductor micromachined electro-mechanical systems (MEMS) technology. Purpose To demonstrate the peculiar characteristics of each probe and the limitations that should be improved. Material and Methods This study was performed from March to April 2018. The only inclusion criterion was the presence of disease, so all patients with musculoskeletal, skin, and subcutaneous pathology were included. A total of 66 patients entered this study. The exams of each patient, with both probes, were evaluated retrospectively and independently by three radiologists. Panoramicity of the images, the definition of superficial structures (<2 cm of depth), the definition of deep structures (>2 cm), and Doppler signal were assessed. A 5-point scale was used for each parameter. Results A total of 89 pathologies were detected. The mean of score for 4G-CMUT was higher than L64 for the panoramicity of the images and the definition of the deep structures. Instead, the mean score for L64 was higher than for 4G-CMUT in the evaluation of superficial structures and Doppler signal. A statistically significant difference was found ( P < 0.05). Conclusion CMUT is a breakthrough in US technology. It allows the use of a single probe for different US examinations. The musculoskeletal, skin, and subcutaneous US can be evaluated with a piezoelectric linear transducer or CMUT. In the present study, the overall diagnostic performance was similar. Improvements in CMUT will provide even more dynamic and flexible imaging capabilities by a transducer, with a wider bandwidth.

A versatile, multi-laser twin-microscope system for light-sheet imaging

Light-sheet microscopy offers faster imaging and reduced phototoxicity in comparison to conventional point-scanning microscopy, making it a preferred technique for imaging biological dynamics for durations of hours or days. Such extended imaging sessions pose a challenge, as it reduces the number of specimens that can be imaged in a given day. Here we present an instrument, the flex-SPIM, that combines two independently controlled light-sheet microscope-twins, built so that they can share an ultrafast near-infrared laser and a bank of continuous-wave visible lasers, increasing throughput and decreasing cost. To permit a wide variety of specimens to be imaged, each microscope-twin provides flexible imaging parameters, including (i) operation in one-photon and/or two-photon excitation modes, (ii) delivery of one to three light-sheets via a trio of orthogonal excitation arms, (iii) sub-micron to micron imaging resolution, (iv) multicolor compatibility, and (v) upright and/or inverted detection geometry. We offer a detailed description of the flex-SPIM design to aid instrument builders who wish to construct and use similar systems. We demonstrate the instrument’s versatility for biological investigation by performing fast imaging of the beating heart in an intact zebrafish embryo, deep imaging of thick patient-derived tumor organoids, and gentle whole-brain imaging of neural activity in behaving larval zebrafish.

Atherosclerosis imaging

Atherosclerosis imaging goes beyond the simple identification of luminal stenosis. Besides stenosis measurement, there are two main motivations for atherosclerosis imaging: one is to identify the so-called vulnerable plaque, defined as atherosclerotic plaque that poses increased risk of rupture and clinical events, such as heart attack or stroke; the other is to identify ‘positively remodelled’ plaques—plaques that grow outward from the lumen but cause minimal or no stenosis. Cardiovascular magnetic resonance (CMR) has histologically validated capabilities to characterize carotid plaque features in vivo, including a lipid-rich necrotic core, fibrous cap, intraplaque haemorrhage (IPH), calcification, and inflammation. A multicontrast two-dimensional imaging approach has been used in many prospective studies relating baseline CMR characteristics of carotid atherosclerosis with plaque progression and clinical events. These studies have demonstrated the importance of detecting IPH, lipid-rich necrotic cores, and fibrous caps. Building on these findings, a number of three-dimensional CMR techniques have been recently developed that allow higher spatial resolution plaque imaging and easier application clinically with short scan times. Three-dimensional plaque imaging offers flexible imaging plane and view angle analysis, large coverage, multivascular beds capability, and is a fast and cost-effective screening for clinical use. Atherosclerosis imaging has also been applied to detect plaques in other vascular beds such as the coronary artery, intracranial artery, and peripheral artery, although each bed comes with unique imaging needs. Large-scale studies are needed to determine the impact of atherosclerotic plaque CMR on patient outcomes.

Terahertz Plasmonics and Nano-Carbon Electronics for Nano-Micro Sensing and Imaging

Sensing and imaging with THz waves is an active area of modern research in optical science and technology. There have been a number of studies for enhancing THz sensing technologies. In this paper, we review our recent development of THz plasmonic structures and carbon-based THz imagers. The plasmonic structures have strong possibilities of largely increasing detector sensitivity because of their outstanding properties of high transmission enhancement at a subwavelength aperture and local field concentration. We introduce novel plasmonic structures and their performance, including a Si-immersed bull’s-eye antenna and multi-frequency bull’s-eye antennas. The latter part of this paper explains carbon-based THz detectors and their applications in omni-directional flexible imaging. The use of carbon nanotube films has led to a room-temperature, flexible THz detector and has facilitated the visualization of samples with three-dimensional curvatures. The techniques described in this paper can be used effectively for THz sensing and imaging on a micro- and nano-scale.