Infrared thermal modulation endoscopy for label-free tumor detection.

In optical imaging of solid tumors, signal contrasts derived from inherent tissue temperature differences have been employed to distinguish tumor masses from surrounding tissue. Moreover, with the advancement of active infrared imaging, dynamic thermal characteristics in response to exogenous thermal modulation (heating and cooling) have been proposed as novel measures of tumor assessment. Contrast factors such as the average rate of temperature changes and thermal recovery time constants have been investigated through an active thermal modulation imaging approach, yielding promising tumor characterization results in a xenograft mouse model.

Orthotopic Mouse Models of Urinary Bladder Cancer.

Background/aim: Urinary bladder cancer has various etiologies and tends to recur and then progress to a higher grade. When muscles are invaded, the response to conventional therapy is poor and the quality of life deteriorates rapidly. Here, we summarize and compare two representative methods used to create the syngeneic mouse models required for immunological research.

Advances in laser speckle imaging: From qualitative to quantitative hemodynamic assessment.

Laser speckle imaging (LSI) techniques have emerged as a promising method for visualizing functional blood vessels and tissue perfusion by analyzing the speckle patterns generated by coherent light interacting with living biological tissue. These patterns carry important biophysical tissue information including blood flow dynamics. The noninvasive, label-free, and wide-field attributes along with relatively simple instrumental schematics make it an appealing imaging modality in preclinical and clinical applications.

Photobiomodulation Therapy Restores Olfactory Function Impaired by Photothrombosis in Mouse Olfactory Bulb.

An ischemic stroke typically accompanies numerous disorders ranging from somatosensory dysfunction to cognitive impairments, inflicting patients with various neurologic symptoms. Among pathologic outcomes, post-stroke olfactory dysfunctions are frequently observed. Despite the well-known prevalence, therapy options for such compromised olfaction are limited, likely due to the complexity of olfactory bulb architecture, which encompasses both the peripheral and central nervous systems.

Fast volumetric imaging with line-scan confocal microscopy by electrically tunable lens at resonant frequency.

In microscopic imaging of biological tissues, particularly real-time visualization of neuronal activities, rapid acquisition of volumetric images poses a prominent challenge. Typically, two-dimensional (2D) microscopy can be devised into an imaging system with 3D capability using any varifocal lens. Despite the conceptual simplicity, such an upgrade yet requires additional, complicated device components and usually suffers from a reduced acquisition rate, which is critical to properly document rapid neurophysiological dynamics.

Nanozyme-based colorimetric biosensor with a systemic quantification algorithm for noninvasive glucose monitoring.

Diabetes mellitus accompanies an abnormally high glucose level in the bloodstream. Early diagnosis and proper glycemic management of blood glucose are essential to prevent further progression and complications. Biosensor-based colorimetric detection has progressed and shown potential in portable and inexpensive daily assessment of glucose levels because of its simplicity, low-cost, and convenient operation without sophisticated instrumentation.

Cranial and Spinal Window Preparation for Optical Neuroimaging in Rodents and Related Experimental Techniques.

Optical neuroimaging provides an effective neuroscience tool for multi-scale investigation of the neural structures and functions, ranging from molecular, cellular activities to the inter-regional connectivity assessment. Amongst experimental preparations, the implementation of an artificial window to the central nervous system (CNS) is primarily required for optical visualization of the CNS and associated brain activities through the opaque skin and bone. Either thinning down or removing portions of the skull or spine is necessary for unobstructed long-term observations, for which types of the cranial and spinal window and applied materials vary depending on the study objectives.

Automated quantification of meibomian gland dropout in infrared meibography using deep learning.

Purpose: Develop a deep learning-based automated method to segment meibomian glands (MG) and eyelids, quantitatively analyze the MG area and MG ratio, estimate the meiboscore, and remove specular reflections from infrared images.

Methods: A total of 1600 meibography images were captured in a clinical setting. 1000 images were precisely annotated with multiple revisions by investigators and graded 6 times by meibomian gland dysfunction (MGD) experts.

Optical Assessment of Tear Glucose by Smart Biosensor Based on Nanoparticle Embedded Contact Lens.

Diabetes is a disease condition characterized by a prolonged, high blood glucose level, which may lead to devastating outcomes unless properly managed. Here, we introduce a simple camera-based optical monitoring system (OMS) utilizing the nanoparticle embedded contact lens that produces color changes matching the tear glucose level without any complicated electronic components. Additionally, we propose an image processing algorithm that automatically optimizes the measurement accuracy even in the presence of image blurring, possibly caused by breathing, subtle movements, and eye blinking.

Open-top axially swept light-sheet microscopy.

Open-top light-sheet microscopy (OT-LSM) is a specialized microscopic technique for high throughput cellular imaging of large tissue specimens including optically cleared tissues by having the entire optical setup below the sample stage. Current OT-LSM systems had relatively low axial resolutions by using weakly focused light sheets to cover the imaging field of view (FOV). In this report, open-top axially swept LSM (OTAS-LSM) was developed for high-throughput cellular imaging with improved axial resolution.

Non-Oncologic Applications of Nanomedicine-Based Phototherapy.

Phototherapy is widely applied to various human diseases. Nanomedicine-based phototherapy can be classified into photodynamic therapy (PDT) and photothermal therapy (PTT). Activated photosensitizer kills the target cells by generating radicals or reactive oxygen species in PDT while generating heat in PTT.

Neurite growth of trigeminal ganglion neurons in vitro with near-infrared light irradiation.

Trigeminal ganglion (TG) neurons play an essential role in the sensory nerves of the face. Damaged TG neurons resulting from the accidental and non-intentional nerve lesions, commonly identified as neuropathic pain, which is known to cause intense pain and sensory abnormalities. For the treatment, surgical methods are conducted when the pharmacological treatment fails to provide satisfactory recovery.

Tear Glucose Measurement by Reflectance Spectrum of a Nanoparticle Embedded Contact Lens.

Glucose level is a primary indicator in the diagnosis and treatment of diabetes mellitus. According to the correlation between glucose concentration in blood and tears, measuring tear glucose can be an alternative to traditional strips test for blood glucose. Thus, measuring tear glucose levels could provide noninvasive monitoring of blood glucose.

Laser speckle decorrelation time-based platelet function testing in microfluidic system.

Platelet aggregation and adhesion are critically involved in both normal hemostasis and thrombosis during vascular injury. Before any surgery, it is important to identify the number of platelets and their functionality to reduce the risk of bleeding; therefore, platelet function testing is a requirement. We introduce a novel evaluation method of assessing platelet function with laser speckle contrast imaging.

Optofluidic laser speckle image decorrelation analysis for the assessment of red blood cell storage.

Red blood cells (RBCs) undergo irreversible biochemical and morphological changes during storage, contributing to the hemorheological changes of stored RBCs, which causes deterioration of microvascular perfusion in vivo. In this study, a home-built optofluidic system for laser speckle imaging of flowing stored RBCs through a transparent microfluidic channel was employed. The speckle decorrelation time (SDT) provides a quantitative measure of RBC changes, including aggregation in the microchannel.

Light sheet microscopy for histopathology applications.

Light sheet microscopy (LSM) is an evolving optical imaging technique with a plane illumination for optical sectioning and volumetric imaging spanning cell biology, embryology, and in vivo live imaging. Here, we focus on emerging biomedical applications of LSM for tissue samples. Decoupling of the light sheet illumination from detection enables high-speed and large field-of-view imaging with minimal photobleaching and phototoxicity.

Fast and sensitive delineation of brain tumor with clinically compatible moxifloxacin labeling and confocal microscopy.

Delineation of brain tumor margins during surgery is critical to maximize tumor removal while preserving normal brain tissue to obtain optimal clinical outcomes. Although various imaging methods have been developed, they have limitations to be used in clinical practice. We developed a high-speed cellular imaging method by using clinically compatible moxifloxacin and confocal microscopy for sensitive brain tumor detection and delineation.

Experimental and computational analyses reveal dynamics of tumor vessel cooption and optimal treatment strategies.

Cooption of the host vasculature is a strategy that some cancers use to sustain tumor progression without-or before-angiogenesis or in response to antiangiogenic therapy. Facilitated by certain growth factors, cooption can mediate tumor infiltration and confer resistance to antiangiogenic drugs. Unfortunately, this mode of tumor progression is difficult to target because the underlying mechanisms are not fully understood.

Multi-Spectral Fluorescence Imaging of Colon Dysplasia InVivo Using a Multi-Spectral Endoscopy System.

Background And Study Aim: To develop a molecular imaging endoscopic system that eliminates tissue autofluorescence and distinguishes multiple fluorescent markers specifically on the cancerous lesions.

Methods: Newly developed multi-spectral fluorescence endoscope device has the potential to eliminate signal interference due to autofluorescence and multiplex fluorophores in fluorescent probes. The multiplexing capability of the multi-spectral endoscope device was demonstrated in the phantom studies and multi-spectral imaging with endoscopy and macroscopy was performed to analyze fluorescence signals after administration of fluorescent probe that targets cancer in the colon.

Planar coil-based contact-mode magnetic stimulation: synaptic responses in hippocampal slices and thermal considerations.

Implantable magnetic stimulation is an emerging type of neuromodulation using coils that are small enough to be implanted in the brain. A major advantage of this method is that stimulation performance could be sustained even though the coil is encapsulated by gliosis due to foreign body reactions. Magnetic fields can induce indirect electric fields and currents in neurons.

Deep brain optical coherence tomography angiography in mice: in vivo, noninvasive imaging of hippocampal formation.

The hippocampus is associated with memory and navigation, and the rodent hippocampus provides a useful model system for studying neurophysiology such as neural plasticity. Vascular changes at this site are closely related to brain diseases, such as Alzheimer's disease, dementia, and epilepsy. Vascular imaging around the hippocampus in mice may help to further elucidate the mechanisms underlying these diseases.

Endoscopic non-ablative fractional laser therapy in an orthotopic colon tumour model.

Colorectal cancer is one of the leading causes of cancer-related deaths. Although several therapeutic management strategies are available at the early colon cancer stages, such as endoscopic mucosal or submucosal dissection, associated complications often include bleeding or bowel perforations. As an alternative approach, we investigated endoscopic non-ablative fractional laser (eNAFL) irradiation as a minimally invasive therapeutic modality for the treatment of early-stage colorectal cancer.