Search Results (4,156)

Recent studies have proposed improving Laser Speckle Contrast Imaging (LSCI) by using polarimetric filtering to isolate multiply scattered photons from moving red blood cells (RBCs), an approach referred to as Laser Speckle Orthogonal Contrast Imaging (LSOCI). This reliance on multiple scattering enables the development of a calibration method based on a moving reference sample, chosen to generate dynamic circular Gaussian speckle fields that replicate the statistical properties of RBC scattering in both intensity and the distribution of polarization states. Assuming that multiply scattered photons from both RBCs and the reference sample exhibit a homogeneous distribution of polarization states over the Poincaré sphere, the proposed calibration links in vivo speckle contrast reduction bijectively to an equivalent speed of the reference sample. We demonstrate that this equivalent-velocity metric yields consistent in vivo measurements across distinct instruments despite the use of different laser spectral widths, thereby providing a standardized and transferable means to quantify microcirculatory activity. Full article

Background: The mucosal barrier presents a significant challenge for non-invasive delivery of macromolecular therapeutics, often requiring administration with poor bioavailability and increased toxicity risks. The polymeric immunoglobulin receptor (pIgR) contains an extracellular secretory component (SC) for immunoglobulin binding and a membrane-anchored stem domain capable of apical-to-basolateral transcytosis. We hypothesized that targeting the stem domain could enable active drug transport across mucosal barriers. Methods: Using phage display, we identified four high-affinity nanobodies against human and murine pIgR. Two lead candidates (3LTHMP-4 and 3LTHMP-5) demonstrated efficient apical-to-basolateral transport in vitro (Transwell assays) and in vivo (fluorescence imaging). Engineered bispecific antibodies fusing these nanobodies with anti-IL-5 mAb reslizumab were administered via inhalation in a murine asthma model at one-tenth the intraperitoneal reslizumab dose. Resluts: The bispecific antibodies showed significant therapeutic efficacy, while reslizumab alone at equivalent concentrations failed to demonstrate efficacy. Hydrogen–Deuterium Exchange Mass Spectrometry (HDX-MS) revealed that both 3LTHMP-4 and 3LTHMP-5 specifically bind to the pIgR stem domain (residues 578–612), a region distinct from the dimeric IgA binding site. Conclusions: These findings suggest that stem domain-specific binding may facilitate transport across the mucosal barrier while preserving native receptor physiology, offering a potential strategy for effective transmucosal delivery of biologics. Full article

Copper ions (Cu²⁺) and intracellular biothiols are tightly coupled in cellular redox regulation, where copper–thiol coordination governs oxidative stress and metal homeostasis. However, analytical platforms capable of sequentially monitoring Cu²⁺ and biothiols within a single molecular system remain scarce. Herein, we report a coumarin-based fluorescent probe XDP that enables sequential ON–OFF–ON sensing of Cu²⁺ and biothiols through a coordination–competition mechanism. The imine (C=N) site of XDP selectively coordinates Cu²⁺, leading to fluorescence quenching arising from coordination-induced electronic perturbation and enhanced nonradiative decay. The probe exhibits a linear response toward Cu²⁺ over 1–80 μM with a detection limit of 0.108 μM. Subsequent competitive binding of biothiols (GSH, Cys, and Hcy) releases Cu²⁺ from the complex, thereby restoring fluorescence and enabling detection within 1–30 μM with submicromolar sensitivity. XDP also displays a large Stokes shift (135 nm), which minimizes spectral overlap and improves signal reliability. Notably, Cu²⁺ binding triggers a distinct color change that supports naked-eye detection and smartphone-based RGB quantification. The probe further enables visualization of Cu²⁺ and thiol-triggered signal recovery in living cells and zebrafish. This work establishes a versatile analytical platform for probing copper–thiol interactions in environmental and biological systems. Full article

Background: Pituitary adenylate cyclase-activating polypeptide (PACAP) functions as an anti-atherogenic neuropeptide. Maxadilan, a PAC1 receptor agonist, offers atheroprotection by acting downstream of vascular inflammation caused by hypercholesterolemia. This study aims to explore how PACAP and Maxadilan influence migration and apoptosis in human coronary artery smooth muscle cells (HCASMCs). Methods: To investigate the role of PACAP deficiency in the pathogenesis of atherosclerosis under standard chow (SC) in vivo, PACAP^−/−-mice were crossed with ApoE^−/−-mice to generate PACAP^−/−/ApoE^−/−-mice. The whole aorta was isolated and stained with OilRedO (ORO). Atherosclerotic lesions and lumen stenosis in the brachiocephalic trunk were quantified using ImageJ 1.54p (Fiji). To further investigate the role of PACAP and Maxadilan in the pathogenesis of atherosclerosis with special respect to HCASMC under a lipid-enriched environment, HCASMCs were treated with oxLDL, with or without PACAP or Maxadilan. Uptake and accumulation of oxLDL were analyzed using Bodipy^TM493/503, and cell viability was assessed with PrestoBlue^®. Cell migration was evaluated using the scratch assay and the MRI wound-healing tool in ImageJ (Fiji). Mitochondrial morphology was examined with MitoTracker Green and the MiNA tool in ImageJ (Fiji). Apoptotic processes were analyzed by Western blot, immunocytofluorescence staining, and ELISA. Results: In vivo, PACAP^−/−/ApoE^−/−-mice showed increased lumen stenosis and decreased plaque burden compared with ApoE^−/−-mice. In vitro, PACAP enhanced the viability of oxLDL-treated HCASMCs, while neither PACAP nor Maxadilan influenced lipid content in HCASMCs, regardless of oxLDL presence. Both oxLDL and PACAP slowed cell migration, but Maxadilan increased migration in oxLDL-treated HCASMCs. The protein level of the proliferation marker Ki67 was reduced in cells treated with oxLDL and Maxadilan. Additionally, BAX, which promotes intrinsic apoptosis, was elevated in HCASMCs stimulated with Maxadilan and oxLDL. Investigations of mitochondrial morphology indicated that oxLDL and PACAP increased the individual and network structures, with a decrease in branches per network. Conclusion: Our data highlight the complex role of the PACAP/PAC1 system in vascular pathology and suggest that selective modulation—such as targeted PAC1 activation or PACAP supplementation—could lead to new strategies for stabilizing atherosclerotic plaques. In the long term, this could improve the balance between plaque formation and vascular function. Full article

Background/Objectives: This review describes the advantages of new photonic-based approaches for assessing the activity of caries lesions. Many lesions have been arrested or are non-carious developmental defects, such as fluorosis, which do not require intervention. New methods are needed to assess lesion activity and avoid unnecessary removal of the tooth structure. Methods: At present, there are no reliable methods for assessing lesion activity in vivo. Nondestructive optical monitoring of lesion structure and the changes in light scattering that occur during drying offer the potential for lesion activity assessment during a single examination. Since optical diagnostic instruments exploit changes in the porosity and the permeability of the lesion, they have the potential to assess whether lesions are active and expanding or arrested and undergoing remineralization. Optical coherence tomography (OCT), Raman imaging and fluorescence loss, thermal and short-wavelength infrared (SWIR) reflectance measurements during lesion dehydration with forced air are presented. Results: Clinical studies have shown that optical coherence tomography is capable of showing distinct structural differences between active and arrested lesions on coronal and root surfaces. Differences in the kinetics of dehydration measured using reflectance measurements at SWIR wavelengths coincident with water absorption bands also show great potential. Conclusions: OCT and dehydration imaging at SWIR wavelengths have great potential for assessing lesion activity since they can also be used for caries screening, are safe for frequent monitoring and do not require the application of external agents. Full article

Orthodontic pain, a fundamental biological response to mechanically induced tooth movement, is primarily associated with sterile inflammation and neurogenic processes within the periodontal ligament (PDL). Although photobiomodulation therapy (PBMT) has been widely investigated as a nonpharmacological approach for pain attenuation, its mechanisms of action remain incompletely understood, and current interpretations are often limited to peripheral anti-inflammatory effects. This review re-examines the biological basis of orthodontic pain by integrating evidence derived predominantly from in vitro and in vivo experimental studies. Particular emphasis is placed on neurogenic inflammation, neuropeptide regulation, and neuron–glia interactions along the trigeminal nociceptive pathway. PBMT can reduce periodontal inflammatory/neuropeptide-related markers and pain-related behaviors in selected models; however, evidence for direct central neuron–glia modulation remains largely marker-based and parameter-dependent. Direct functional validation of trigeminal circuit modulation (e.g., electrophysiological recordings or calcium imaging) remains limited in orthodontic pain models; thus, the proposed neuroimmune mechanisms should be interpreted as testable hypotheses for future work. By synthesizing mechanistic insights across multiple biological levels, this review proposes a broader framework for understanding PBMT-mediated pain modulation extending beyond conventional peripheral models. These perspectives may help clarify inconsistencies in the reported outcomes and provide a rationale for future hypothesis-driven experimental and translational research. Full article

Psilocybin, a psychedelic drug with reported anxiolytic and antidepressant potential, is rapidly metabolized to its active metabolite psilocin. However, a lack of adequate toxicity studies and tissue distribution studies currently restricts its development and application. This study combined behavioral assays in zebrafish with desorption electrospray ionization mass spectrometry imaging (DESI-MSI) to systematically evaluate the acute neurotoxicity of psilocybin and characterize the in vivo spatial distribution of its active metabolite, psilocin. The novel tank test was used to evaluate zebrafish following a 4 h exposure to psilocybin at three different doses (20, 40, and 80 μM; n = 6 per group). Statistical analysis of the data was performed using ANOVA. Behavioral analyses revealed that exposure to psilocybin induced pronounced neurobehavioral alterations, including hyperactivity and disrupted swimming patterns, as evidenced by significant increases in the number of zone transitions and shuttle frequency. We established a DESI-MSI-based method for quantitative mapping and visualization of psilocin in zebrafish tissues. Methodological validation indicated that a linear relationship between ion intensity, spotted amount (R² = 0.9947), and reproducibility (RSD < 15%) is suitable for quantitative analysis of psilocin in zebrafish tissues. Spatial distribution maps showed that following continuous exposure for 4 h, psilocin was widely distributed across multiple tissues, such as the eye, brain, heart, liver, and kidney, with marked accumulation in the brain and the periportal regions of the liver. Relative psilocin signal intensity revealed a dose-dependent increase in tissue drug levels. The dose-dependent increase in both behavioral hyperactivity and brain psilocin levels points to a consistent relationship, in line with a central site of action. Collectively, these findings demonstrate that DESI-MSI provides a visual and efficient strategy for studying drug distribution in biological tissues from exposed animals. The neurobehavioral toxicity phenotypes and distinct tissue distribution patterns of psilocin uncovered in this study offer critical insights into the biological effects and potential risks of this psychoactive substance. Full article

Ovarian cancer (OC) is typically treated with cytoreductive surgery (CRS). Hyperspectral imaging (HSI) is an emerging non-invasive, label-free technique that enables whole-area scanning, making it a promising tool for real-time tumour recognition. However, developing tumour recognition algorithms requires a foundational understanding of spectral variability in normal tissues. This study focusses on the in vivo spectral profiles of key abdominal and pelvic organs encountered during CRS, including the uterus, ovaries, intestines, mesentery, omentum, peritoneum, and fallopian tubes, and evaluates the potential for organ recognition using HSI data. Intraoperative HSI data were from healthy patients. Two machine learning models, a support vector machine (SVM) and a 3D convolutional neural network (3DCNN), were trained to classify the organs based on their spectral signatures. In total, 15 patients were included in the dataset. The 3DCNN slightly outperformed the SVM in terms of the average accuracy (0.889 vs. 0.878), sensitivity (0.648 vs. 0.604), specificity (0.936 vs. 0.930), and Dice Similarity Coefficient (0.595 vs. 0.569). This study demonstrates the feasibility of using HSI for organ differentiation in the clinical setting, although in some cases separability remains a challenge, especially when organs have similar spectra. This is a critical step towards a generalizable in vivo abdominal tumour recognition algorithm, by carefully investigating spectral fingerprints of abdominal tissues. Full article

Imaging of infections has the potential to improve clinical outcomes, but pathogen-specific imaging strategies are currently unavailable. Given their target specificity, antimicrobials may be useful as molecular imaging ligands to target infections. Despite substantial development efforts, no antimicrobial-based ligands are approved for clinical use. This scoping review comprehensively surveys radiolabeled antimicrobials across antibacterial, antimycobacterial, antiviral, and antifungal drug classes, examining their progression through the translational pipeline. The review utilized PubMed and Google Scholar databases (1970–2025), following PRISMA Extension for Scoping Reviews (PRISMA-ScR) guidelines. Two reviewers independently screened titles, abstracts, and full-text articles; data were extracted, and content duplicates were removed. In total, 143 preclinical and 25 clinical articles met the selection criteria. In clinical studies, most tracers showed suboptimal specificity for infections, while some proved useful for pharmacokinetic characterization. Among preclinical studies, radiolabeled plazomicin and echinocandins (caspofungin and anidulafungin) exhibited the greatest number of preferred characteristics. In conclusion, ideal antimicrobial pharmacologic properties can be counterproductive for imaging, where rapid background clearance and a high target-to-non-target ratio (T/NT) are essential. Many radioligands demonstrate good tissue penetration but suboptimal washout, limiting their diagnostic value. In vivo pharmacokinetic applications during active infections are promising, though significant challenges remain for infection imaging. Full article

Background: Uncontrolled hemorrhage, especially at non-compressible sites, remains a major cause of preventable trauma deaths. This study reports the development of fibrinogen-loaded calcium carbonate (CaCO₃) microparticles that combine hemostatic activity with self-propelling capability for targeted delivery against blood flow, with a focus on understanding formulation-dependent trade-offs among particle yield, protein loading, clotting performance, and transport behavior. Methods: Microparticles were synthesized via a precipitation method using different carbonate sources and characterized for yield, morphology, size, and fibrinogen encapsulation. Hemostatic function was assessed using rotational thromboelastometry (ROTEM) in fibrinogen-deficient plasma. Propulsion behavior was evaluated following exposure to protonated tranexamic acid (TXA⁺), which triggers CO₂ generation. Particle size and encapsulation were examined by microscopy and fluorescence imaging. Results: The precipitation method produced spherical micrometer-sized particles, with fibrinogen inclusion reducing yield and particle size relative to unload controls. Fluorescence microscopy confirmed successful encapsulation. Encapsulation efficiency varied with formulation, with sodium carbonate-based particles showing higher relative fibrinogen loading. ROTEM analysis demonstrated that fibrinogen-loaded particles significantly improved clot formation, increasing maximum clot firmness compared to fibrinogen-free particles, although performance remained formulation-dependent. TXA⁺-triggered propulsion achieved maximum speeds up to 4.221 cm/s. Fibrinogen-loaded particles exhibited longer activation lag times than unloaded particles, indicating a trade-off between hemostatic functionality and propulsion kinetics. Conclusions: Fibrinogen-loaded CaCO₃ microparticles exhibit both hemostatic activity and chemically triggered motion in vitro. The study identifies key formulation-dependent trade-offs between particle yield, fibrinogen loading, clotting performance, and propulsion behavior. While these findings support the feasibility of combining localization and clot stabilization mechanisms, further studies under physiologically relevant flow conditions and in vivo models are required to evaluate their potential for active delivery in non-compressible hemorrhage. Full article

Background/Objectives: Intraoperative fluorescence imaging (FI) with tumor-targeted tracers offers a promising approach to improve surgical precision in cancer surgery. cRGD-ZW800-1, an integrin-targeted fluorescent tracer, has previously demonstrated safety, tumor specificity, and utility in detecting inadequate margins in oral cancer. During this study, we observed variability in background fluorescence between different subsites of the oral cavity. Therefore, this study aimed to systematically evaluate intraoperative in vivo and ex vivo mucosal contrast ratios across various oral cavity subsites using FI with cRGD-ZW800-1. Methods: Thirty-one patients with oral squamous cell carcinoma underwent intraoperative FI following intravenous injection of cRGD-ZW800-1 at least 18 h preoperatively. In vivo imaging was performed using the Quest Spectrum platform. In addition, ex vivo FI of the resected specimen was performed using the Pearl Trilogy Small Animal Imaging System. As these ex vivo images were obtained under uniform and controlled acquisition conditions, they allow for direct comparison with the intraoperative fluorescence signals. Fluorescence intensities and tumor-to-background ratios (TBRs) were assessed per oral subsite using manually drawn regions of interest (ROIs) on the tumor and adjacent healthy mucosa using Quest’s Spectrum Software, version 4.8.2, (in vivo images) and the Pearl’s integrated software ImageStudio version 6.2 (ex vivo images). A TBR ≥ 1.5 was considered sufficient. Results: Under uniform imaging settings, all samples exhibited adequate contrast (TBR ≥ 2.3), allowing clear tumor visualization and precise evaluation of mucosal margins on final histopathology. Notably, intraoperative in vivo contrast in the posterior located maxillary alveolar process was comparatively lower, which was attributable to suboptimal imaging conditions and subsite-specific background fluorescence. Conclusions: Our findings indicate that, although contrast varies across different oral subsites, all specimens exhibited sufficient ex vivo mucosal contrast to allow reliable tumor delineation. As in vivo imaging may be affected by subsite-specific background fluorescence and inherent limitations of intraoperative imaging geometry, fluorescence signals should be interpreted in conjunction with standard visual and tactile assessment. Due to anatomical constraints, different oral subsites may appear within the same field of view, which can influence perceived signal intensity. Therefore, intraoperative ex vivo fluorescence evaluation is recommended for signal interpretation. Full article

Radiolabelled nanoparticles are increasingly investigated as multifunctional platforms for cancer imaging, biodistribution tracking, dosimetry, and radionuclide-based therapy. This review focuses on three representative inorganic nanoplatforms: zinc oxide (ZnO), iron oxide-based, and gold (Au) nanoparticles. These systems were selected because they combine distinct physicochemical properties with versatile surface engineering and radiolabelling strategies. ZnO nanoparticles offer pH-responsive behaviour and drug-delivery potential; iron oxide-based nanoparticles provide magnetic functionality, Magnetic resonance imaging (MRI) compatibility, and opportunities for magnetic hyperthermia or local nanobrachytherapy; and Au nanoparticles enable stable surface functionalization, radiometal chelation, radiosensitisation, photothermal effects, and alpha or beta-emitter-based local therapy. The review critically discusses synthesis and surface-modification methods, chelator-mediated and chelator-free radiolabelling, coating-assisted and anchoring-mediated strategies, and the influence of these factors on radiochemical stability, biodistribution, tumour uptake, therapeutic response, toxicity, and clearance. A function-based comparison of the reviewed studies highlights that many systems demonstrate efficient radiolabelling and imaging capability, whereas fewer provide direct in vivo therapeutic efficacy, long-term toxicity, or metabolic clearance data. Overall, radiolabelled ZnO, iron oxide-based, and Au nanoparticles show strong potential for cancer theranostics, tumour-to-organ distribution, therapeutic benefit, and safety. Full article

Photonic imaging technologies have profoundly transformed neuro-ophthalmic diagnostics by enabling non-invasive visualization of neurodegenerative processes at the retinal level. This review examines how advanced light-based modalities provide unprecedented insights into the structural, physiologic, and biologic relationships between the eye and brain in conditions such as optic neuritis, multiple sclerosis, and glaucoma. Optical coherence tomography has emerged as an essential tool for quantifying thinning of the retinal nerve fiber layer and ganglion cell layer, serving as reliable biomarkers of axonal loss and disease progression across multiple sclerosis subtypes and optic neuropathies. Detection of apoptosing retinal cells imaging enables real-time visualization of retinal ganglion cell apoptosis preceding irreversible structural damage, offering a critical window for early intervention in various neurodegenerative conditions, in particular, glaucoma. Two-photon microscopy with adaptive optics enables subcellular-resolution imaging of retinal neurons, microvascular dynamics, and inflammatory processes in vivo, facilitating the characterization of neurodegenerative mechanisms at unprecedented spatial scales and redefining neuro-ophthalmology by positioning the retina as an accessible extension of the central nervous system. This review critically examines how established and investigational photonic imaging modalities may support earlier disease detection, longitudinal monitoring, and biomarker development in neuro-ophthalmic and neurodegenerative disorders, with potential implications for more timely and targeted management strategies. Full article

Background/Objectives: Pediatric group 3 (G3) medulloblastomas (MB) are therapy resistant and have a significantly worse prognosis than the other MB subtypes. Aggressive radiation/chemotherapy improves survival, but potential long-term comorbidities include neurocognitive deficits. In previous work, we demonstrated that low-dose X-ray radiation (LDXR) acts as an immunological adjuvant. Recent studies have demonstrated that galectin-3 (Gal-3) expression in MB tumors accelerates M2 macrophage infiltration and restricts T cell receptor (TCR)-mediated signaling. Immunotherapy with an agonistic anti-4-1BB monoclonal antibody (mAb) activates CD8+ T cells, promoting their survival and acquisition of potent cytolytic properties. Building on these findings, we hypothesized that immune priming via sublethal LDXR, combined with a Gal-3 inhibitor and an anti-4-1BB mAb, would boost anti-tumor effects, resulting in survival benefits. Methods: We tested this hypothesis in vitro in co-cultures of human MB cells and in vivo, in an immunocompetent G3MB mouse model (MP1). Treatment effects were assessed using Western blot, flow cytometry, hematoxylin and eosin (H&E) staining, immunofluorescence imaging, and analysis of cytokine and chemokine expression. Results: Our data demonstrated higher Gal-3 expression in MB patient-derived tumor tissue than in non-tumor tissue. LDXR modulated major histocompatibility complex molecules, and, combined with a Gal-3 inhibitor and an anti-4-1BB mAb, altered T-cell/tumor-cell interactions, enhanced T-cell-mediated MB cell death, and shifted cytokine production to drive microglial polarization toward the M1 subtype. Furthermore, H&E-stained tumor sections showed a ~70% reduction in tumor size compared with untreated controls. Conclusions: These preclinical findings suggest that combining immune priming with sublethal LDXR, Gal-3 inhibition, and 4-1BB activation may be an effective treatment strategy for G3MB. Full article

Alzheimer’s disease (AD) is a heterogeneous neurodegenerative disorder driven by complex interactions between genetic susceptibility, molecular pathways, and progressive brain alterations. Key genetic factors, including APOE, TREM2, and MAPT, contribute to pathological processes such as amyloid-β accumulation, tau aggregation, neuroinflammation, and synaptic dysfunction. Despite substantial advances in understanding these mechanisms, translating molecular insights into clinically accessible biomarkers remains a major challenge. Radiomics and machine learning (ML) have emerged as promising approaches for extracting high-dimensional quantitative features from medical imaging data and identifying complex patterns associated with disease processes. Radiomic features capture spatial heterogeneity and subtle characteristics of neurodegeneration that are not discernible using conventional imaging analysis. When integrated with ML, these features may serve as noninvasive surrogates of molecular activity, enabling the identification of imaging signatures associated with specific genetic backgrounds and biological pathways. This review aims to explore how radiomics and ML can bridge the gap between genetic and molecular mechanisms and in vivo imaging phenotypes in AD. We summarize current knowledge on genetic determinants and molecular pathways and discuss advances in molecular imaging, particularly tracers targeting amyloid and tau pathology. Furthermore, we analyze the emerging role of radiomics and ML in linking imaging phenotypes with underlying biological processes. This integrative framework may support improved disease stratification, early diagnosis, and prediction of therapeutic response, contributing to the development of precision medicine strategies and future theranostic approaches in Alzheimer’s disease. Full article