Search Results (750)

Background/Objectives: The precise elimination of Schistosoma japonicum eggs within host tissues poses a significant therapeutic obstacle due to the ineffectiveness of existing drugs in penetrating the eggs’ protective shields. This investigation sought to create a surface-modified magnetic nanoparticle (MNP) framework to surmount this hurdle and realize targeted theranostics for combating schistosomiasis. Methods: Fe₃O₄ MNPs, MNP-NH₂, and MNP-COOH were synthesized and characterized before systematically studying their interactions with parasites. The intrinsic autofluorescence of eggs and adult worms served as an optical background for the investigation. In vitro co-incubation assays, confocal microscopy, and Prussian blue staining were utilized to quantify both adsorption and internalization. The in vivo efficacy was assessed in a Schistosoma japonicum murine model following tail vein injection. Results: A pronounced surface chemistry-dependent interaction was noted. Fe₃O₄ MNP and MNP-NH₂ displayed remarkable adsorption and effective internalization into eggs in vitro, while MNP-COOH exhibited limited uptake. This varying effectiveness was similarly observed in vivo, with Fe₃O₄ MNP and MNP-NH₂ predominantly gathering in hepatic granulomas and effectively infiltrating deposited eggs. Within adult worms, Fe₃O₄ MNP and MNP-COOH exhibited distribution on the tegument and within adult worms. Conclusions: We developed a functional MNP platform in which surface charge governs parasiticidal targeting. Among the candidates investigated, MNP-NH₂ proved to be the most efficient for egg-targeted theranostics. This study introduces an innovative nanotechnology-based approach for accurate diagnosis and treatment of schistosomiasis by specifically tackling the challenge of impermeable eggs. Full article

Laser-induced autofluorescence (LIAF) spectroscopy is a label-free optical technique sensitive to biochemical and structural tissue properties. Its application in upper aerodigestive tract malignancies is in its early stages. This study evaluates the feasibility of a matrix scan-based LIAF approach for examining differences between normal and malignant tissues. An exploratory case series involving three patients with oropharyngeal malignancies was conducted. Tissue sections from normal and tumor regions were analyzed using LIAF spectroscopy, including intensity and lifetime measurements, implemented through a matrix scanning protocol with fixed excitation, detection sensitivity, and sample thickness. Complementary Fourier-transform infrared (FTIR) spectroscopy was used to qualitatively assess biochemical variations, and spectroscopic findings were correlated with histopathological evaluation. Within individual cases, consistent differences in autofluorescence spectral and lifetime characteristics were observed between benign and malignant tissue regions. FTIR analysis revealed concurrent biochemical variations that qualitatively supported the autofluorescence observations. This exploratory study demonstrates the potential of combining LIAF matrix scan with FTIR spectroscopy to investigate tissue-specific spectral variations in upper aerodigestive tract lesions. The findings are preliminary and motivate further investigation using larger patient groups and clinically relevant acquisition conditions. Full article

Background and Objectives: To evaluate the occurrence of retinal displacement using blue-fundus autofluorescence (BFAF) imaging in eyes treated for primary rhegmatogenous retinal detachment (RRD) and its associations with clinical factors, including macular status, detachment extent, baseline visual acuity, high myopia, postoperative visual recovery, and metamorphopsia. Materials and Methods: This retrospective observational study included 98 patients who underwent surgery for primary RRD at a single center. Surgical approaches included pars plana vitrectomy (PPV), phacovitrectomy, or scleral buckling, with tamponade agents such as SF₆ gas (20%), silicone oil (≈1300 cSt), or air. Postoperative BFAF imaging assessed retinal displacement. Demographic and clinical data were recorded. Results: Macula-off detachments occurred in 56.1% of cases, while 43.9% were macula-on detachments. Phacovitrectomy was performed in 41.8%, simple vitrectomy in 33.7%, and scleral buckling in 24.5%. SF₆ gas was the most used tamponade, while silicone oil was used in 13.3%. Retinal displacement was detected in 16.3% of cases, predominantly downward (81.25%) and less commonly upward (18.75%). Macula-off detachments were significantly associated with displacement (81.2% vs. 51.2%, p = 0.027). No significant associations were found with other parameters. Metamorphopsia was reported in 12.5% of patients with displacement and 4.9% without, though the difference was not statistically significant. Conclusions: Retinal displacement can occur after primary RRD repair, irrespective of tamponade, though it tended to be less frequent with silicone oil and in macula-on detachments. It is significantly more common in macula-off cases, even with immediate postoperative prone positioning. These findings emphasize the need to refine postoperative positioning protocols to reduce displacement and its sequelae. Further studies should explore the impact of retinal displacement on visual function, particularly metamorphopsia, in patients with preserved best-corrected visual acuity. Full article

Fluorescence imaging is crucial for providing detailed information in clinical practice. However, traditional first near-infrared (NIR-I) dyes such as indocyanine green (ICG) exhibit limitations such as shallow penetration depth, low contrast, and suboptimal clarity due to light scattering and autofluorescence. To overcome these drawbacks, we utilized a novel amphiphilic second near-infrared (NIR-II) aggregation-induced emission (AIE) probe (TCP) with an emission range beyond 1300 nm (NIR-IIa). Using approximately 200 co-registered NIR-I/NIR-IIa image pairs acquired with TCP, we trained a SwinUnet-based deep learning model to transform low-quality NIR-I ICG images into high-resolution NIR-IIa-like images. Owing to its superior brightness and photostability, TCP enhances in vivo fluorescent angiography, offering clearer vascular details and a higher signal-to-background ratio (SBR) in the NIR-IIa region, 2.6-fold higher than that of ICG in the NIR-I region. The deep learning model successfully converted blurred NIR-I images into high-SBR NIR-IIa-like images, achieving rapid imaging speeds without compromising quality. This work introduces a synergistic “probe-plus-AI” paradigm that substantially improves both the quality and speed of clinical fluorescence imaging, providing a pathway that is immediately translatable to enhanced diagnostics and image-guided surgery. Full article

Multiphoton endomicroscopy (MPEM) has recently become a key development in optical biomedical diagnostics, providing histologically relevant in vivo images that are eliminating both the need for tissue damage during biopsy sampling and the need for dye injections. Due to its ability to visualize structures at the epithelial, extracellular matrix, and subcellular levels, MPEM offers a promising diagnostic method for precancerous conditions and early forms of gastrointestinal (GI) cancer. The high specificity of multiphoton signals—the two-photon fluorescence response of endogenous fluorophores (NADH, FAD), the second-harmonic generation signal from collagen, and others—makes this method a promising alternative to both traditional histology and confocal endoscopy, enabling real-time assessment of metabolic status, intestinal epithelial cell status, and stromal remodeling. Despite the promising prospects of multiphoton microscopy, its practical implementation is progressing extremely slowly. The main factors here include the difficulty of delivering ultrashort pulses with high peak power, which is necessary for multiphoton excitation (MPE), and obtaining these pulses at the required wavelengths to activate the autofluorescence mechanism. One of the most promising solutions is the use of specialized multimode optical fibers that can both induce beam self-cleaning (BSC), which allows for the formation of a stable beam profile close to the fundamental mode, and significantly broaden the optical spectrum, which can ultimately cover the entire region of interest. This review presents the biophysical foundations of multiphoton microscopy of GI tissue, existing endoscopic architectures for MPE, and an analysis of the potential for using novel nonlinear effects in multimode optical fibers, such as the BSC effect and supercontinuum generation. It is concluded that the use of optical fibers in which the listed effects are realized in the tracts of multiphoton endomicroscopes can become a key step in the creation of a new generation of high-resolution instruments for the early detection of malignant neoplasms of the GI tract. Full article

Tyrosinase, encoded by Tyr, is a key rate-limiting enzyme in melanin biosynthesis. Knockout of Tyr results in a distinct albino phenotype, making it a widely used target for evaluating gene-editing efficiency. Here, we found that the tyrosinase-deficient skin melanophore lineage of Xenopus tropicalis (X. tropicalis) tadpoles shows strong autofluorescence under the GFP filter, which may interfere with in vivo fluorescence imaging. Through spectral scanning analysis, we characterized the emission spectrum of the autofluorescence under commonly used excitation wavelengths for fluorescent proteins. Based on this, we established a reference protocol for identifying and excluding such interference in Tyr-targeted knockin studies. Furthermore, knockout of the GTP cyclohydrolase 2 gene (Gch2) using CRISPR-Cas9 significantly reduced the fluorescence intensity induced by tyrosinase deficiency, indicating an essential role of the enzyme and its mediated pterine biosynthesis in the generation of the autofluorescence. This study systematically characterized these fluorescent mutant melanophores in X. tropicalis tadpoles, providing a practical basis for avoiding fluorescent interference in experimental science and a new perspective on pigment cell development and evolution. Full article

Next-generation therapeutic devices will rely on an intelligent integrated system that consolidates multiple functions into a single platform. These individual chemical components exhibit diverse physicochemical properties, demonstrating multifunctional characteristics. In this review, we focus on how the distinctive properties of upconversion nanoparticles (UCNPs), achieved via refined preparation methods, unlock novel functionalities in biomedical applications. Specifically, features such as near-infrared excitation, deep-tissue penetration, low autofluorescence, and tunable multicolor emission endow UCNPs with substantial potential in fields including deep-tissue imaging, targeted drug delivery, and photodynamic therapy. This article systematically reviews recent advances in the design and functionalization of UCNPs, elucidating their role in facilitating the development of integrated diagnostic and therapeutic platforms and fostering the establishment of intelligent responsive treatment systems. Finally, we address current technical challenges—including uniformity in large-scale production, long-term biosafety, and in vivo metabolic mechanisms—and provide insights into future interdisciplinary integration, clinical translation pathways, and their potential role in personalized medicine. Full article

Background: Evidence guiding secondary repair of persistent full-thickness macular holes (FTMHs) remains limited and heterogeneous. Temporal arcuate relaxing retinotomy has been described as a salvage maneuver intended to increase temporal retinal compliance, yet functional safety data are scarce. We report consecutive real-world outcomes of temporal arcuate relaxing retinotomy for persistent FTMHs after failed standard repair(s). Methods: Retrospective consecutive case series of patients with persistent FTMH after ≥1 pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling, treated with repeat PPV and temporal arcuate relaxing retinotomy. Outcomes included OCT (Optical Coherence Tomography)-confirmed closure after gas absorption and best-corrected visual acuity (BCVA, logMAR), ellipsoid zone (EZ) status, retinotomy-site morphology on OCT/fundus autofluorescence (FAF), and safety/functional outcomes (systematic scotoma symptom inquiry; Humphrey visual field testing when feasible). Exact binomial 95% confidence intervals (CI) were calculated for proportions. Results: Nine eyes (median age 70 years; range 55–76) underwent temporal arcuate relaxing retinotomy for persistent FTMH. Minimum linear diameter ranged 412–1037 µm (median 613 µm). OCT-confirmed closure was achieved in 7/9 eyes (77.8%; 95% CI 40.0–97.2) at a mean follow-up of 5.9 months (range 2–12). BCVA improved in 8/9 eyes (88.9%; 95% CI 51.8–99.7); mean BCVA improved from 1.26 ± 0.51 logMAR pre-operatively to 0.61 ± 0.18 logMAR at last follow-up (mean change −0.64 logMAR; Wilcoxon signed-rank test p = 0.011). As a sensitivity analysis, the paired t-test yielded p = 0.008. Humphrey visual fields were obtained in 6/9 eyes; one patient reported a new paracentral nasal scotoma, which was subjectively well tolerated. Conclusions: In this small consecutive series, temporal arcuate relaxing retinotomy was associated with a 78% closure rate and mean BCVA improvement in eyes with persistent FTMH after failed standard repair(s), with limited symptomatic scotoma reporting in those assessed. Given the retrospective design, small cohort, and incomplete standardized functional testing, larger comparative studies with uniform functional endpoints (microperimetry, RNFL/GCL metrics, and systematic perimetry) are needed to define patient selection, reproducibility, and relative performance versus contemporary salvage options. Full article

Background/Objectives: Advanced glycation end products (AGEs) and carotenoids are systemic indicators of metabolic and oxidative status, yet their influence on ocular tissue biomechanics remains unclear. This study investigated the relationships between systemic AGEs and skin carotenoid levels, as well as corneal biomechanical properties in glaucoma patients. Methods: A retrospective observational analysis was performed on 676 patients (1278 eyes) who attended the glaucoma clinic at Shimane University Hospital between May 2019 and August 2024. Fingertip skin autofluorescence (sAF)-based AGE scores using AGE Sensor^® and skin carotenoid scores using the Veggie Meter^® were collected as part of systemic evaluation. Corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-correlated intraocular pressure (IOPg), and corneal compensated intraocular pressure (IOPcc) were measured using the ocular response analyzer (ORA). Associations between systemic variables, AGEs, carotenoids, and ORA parameters were analyzed using univariate tests, mixed-effects regression models, and quartile-based comparisons. Results: The mean AGEs and carotenoid scores were 0.42 ± 0.10 arbitrary units and 338.5 ± 130.8 optical density units, respectively. Via a univariate analysis, an inverse association was found between carotenoid level and CRF; however, via multivariate analyses, neither AGEs nor carotenoid levels were associated with IOPg, IOPcc, CH, or CRF in any analysis. In contrast, demographic parameters showed significant associations with ORA parameters. Via quartile-based comparisons, a significant inverse correlation was found between AGEs and carotenoids (p < 0.0001). Conclusions: In conclusion, sAF-measured AGEs and skin carotenoids showed no remarkable associations with corneal biomechanical properties. AGEs and carotenoids demonstrated an inverse relationship with each other, and each marker was associated with several demographic parameters. Full article

A strain of aeroterrestrial green microalgae Coelastrella rubescens IBSS-156, isolated from an epilithic lichen, has been previously shown to efficiently produce green biomass and accumulate significant amounts of secondary carotenoids. In this study, using a two-stage batch culture, we analyzed time-course changes in variable chlorophyll a (Chl a) fluorescence parameters. Additionally, regression models were developed to correlate autofluorescence signals with spectrophotometric measurements of Chl a and total carotenoid content. Maximum quantum efficiency of photosystemII (F_v/F_m) remained high throughout the vegetative stage. At the end of this stage, under nutrient-limited conditions, the relative electron transport rate (rETR) declined to half its peak value during exponential growth. Stress induced a strong response in the algal photosynthetic apparatus during the early red stage. Within the first three days, F_v/F_m and rETR remained extremely low, but both increased sharply by day 5. During secondary carotenoid accumulation, fluorescence parameters remained at 70–80% of the vegetative-stage maximum, followed by a sharp decline toward the end of the red stage. Therefore, changes in variable fluorescence parameters can serve as markers of C. rubescens cellular physiology during biotechnological cultivation, denoting the completion of specific stages. Flow cytometry and pigment assay regression enabled real-time monitoring of C. rubescens biomass and carotenoids. Full article

The consumption of virgin olive oil has been associated with a broad spectrum of beneficial effects. These health outcomes are attributed not only to its high monounsaturated fatty acid content but also to its bioactive components. Nowadays, the flavoring of olive oil has gained popularity to improve its antioxidant properties, modify its sensory characteristics, and enhance its oxidative stability. This study explores spectrofluorometry as a fast, non-destructive, and eco-friendly tool to monitor oxidation and predict shelf life in virgin olive oils (VOOs). Both unflavored and flavored rosemary and basil samples were studied. Over nine months of storage, monthly autofluorescence measurements at 330 nm excitation revealed dynamic spectral changes. These changes were mapped into three distinct emission zones (I, II, and III), providing a spectral fingerprint of oil freshness and stability. Autofluorescence analysis revealed that oxidation-related emission increased while pigment-related emission decreased over time, especially within the first five months. Rosemary and basil flavoring slowed degradation due to antioxidant migration from the herbs. It is proposed that a ratio between the fluorescence intensity of Zone III/Zone II of the spectrum of less than 0.6 indicates oils stored for more than three months. Full article

Background/Objectives: Pigment migration is a key biomarker of progression in age-related macular degeneration (AMD). This study assessed the diagnostic performance of ring aperture Retro mode (RAR) imaging for detecting pigment migration and compared its performance with established multimodal imaging techniques. Methods: This retrospective study included 80 eyes from 61 consecutive patients with AMD who underwent multimodal imaging with color fundus images (CFIs), fundus autofluorescence (FAF), RAR imaging (Mirante, NIDEK), and en face optical coherence tomography (OCT) with B-scans (Cirrus HD-OCT 5000, Zeiss). Two independent retina specialists graded the AMD stage and the presence of pigment migration across modalities. Sensitivity and positive predictive value (PPV) of RAR were calculated using en face OCT as the reference standard. Results: RAR demonstrated high diagnostic performance, with a sensitivity of 94.7% and a PPV of 93.4% relative to en face OCT. RAR frequently identified pigment migration that was not visible on CFI or FAF, particularly in early AMD and in eyes with media opacity. Distinct morphologic patterns—including hyperreflective foci, thickened retinal pigment epithelium, refractile drusen, and cuticular drusen—were consistently identifiable on RAR. In four eyes with geographic atrophy, RAR detected perifoveal pigment redistribution at least six months before foveal involvement was confirmed by OCT and FAF. Conclusions: RAR imaging is a rapid, sensitive, and clinically practical technique for detecting pigment migration in AMD. By complementing en face OCT and enhancing visualization in cases where standard imaging is limited, RAR may strengthen early disease surveillance, support prognostic assessment, and improve multimodal diagnostic workflows in routine practice. Full article

Since the early development of Fluorescence Correlation Spectroscopy (FCS), it has been recognized that background intensity can lead to artifacts in the amplitude of the autocorrelation function (ACF) and, consequently, to inaccurate estimates of particle numbers. Here, we present a protocol for quantitative background evaluation and amplitude correction in FCS experiments, applicable to different sources of background such as detector noise, autofluorescence, and light scattering. We demonstrate the performance of our approach through three representative case studies: (i) FCS measurements of a bright fluorophore at low concentration, (ii) FCS of dim nanoparticles affected by solvent Raman scattering, and (iii) FCS performed using a confocal setup equipped with a SPAD array, where background originates from detector hot pixels. These examples represent typical experimental conditions in which background signals compromise quantitative interpretation, illustrating how our protocol restores accuracy and reproducibility in FCS analysis. By systematically identifying and correcting these effects, the proposed protocol addresses a long-standing limitation of FCS and provides a robust framework for improving the accuracy and reproducibility of quantitative fluorescence measurements. Full article

Background/Objectives: Skin autofluorescence (SAF), a marker of advanced glycation end products (AGEs), reflects cumulative hyperglycemia and may predict vascular complications in diabetes. Continuous glucose monitoring (CGM) also provides detailed glycemic profiles, but their prognostic values in gestational diabetes mellitus (GDM) are unclear. The primary aim was to evaluate whether SAF predicts adverse maternal or neonatal outcomes, whereas secondary exploratory analyses assessed oxidative stress markers and CGM-derived metrics. Methods: We prospectively enrolled 115 Japanese pregnant women with plasma glucose ≥ 140 mg/dL at 60 min after 50-g GCT. At around 29 weeks’ gestation, SAF and diacron-reactive oxygen metabolites (d-ROMs) were measured, and a subset underwent 14-day CGM. Maternal and neonatal outcomes were obtained from medical records. Logistic regression and receiver operating characteristic (ROC) analyses were performed. Results: In the primary analysis of the overall cohort, SAF did not predict adverse outcomes. In the CGM subgroup, mean glucose level (MGL) was significantly higher in women with maternal complications. Multivariate analysis identified MGL as the only independent predictor of maternal adverse events (adjusted OR 10.45 per 10 mg/dL, 95% CI 1.93–56.5; AUC 0.818; cutoff 86.8 mg/dL). No marker predicted neonatal outcomes. Conclusions: The pre-specified primary endpoint was negative (SAF was not predictive), and oxidative stress markers were also not predictive, whereas CGM-derived MGL independently predicted maternal adverse outcomes, underscoring the utility of CGM for risk stratification in pregnant women with abnormal GCT results. Full article

Animal cruelty investigations can be hampered by not knowing when a biological sample was deposited at a crime scene, i.e., the sample’s time-since-deposition (TSD). The goal of this study was to characterize a new signature system for estimating the TSD of canine blood samples based on changes in the autofluorescence spectra of cell populations that occur over time. The results showed that the intensity of cellular autofluorescence measured in two detector channels (523/30 nm and 695/50 nm; 488 nm excitation) could clearly differentiate older blood deposits (i.e., samples with a TSD of either 6 months or 1 year) from younger samples that had a TSD of less than three months. Further, cellular autofluorescence was strongly correlated with time when the sample TSD was between one day and three months, with correlation coefficients ranging between 0.83 and 0.91. A multiple linear regression model based on autofluorescence variation was tested on mock casework samples and yielded residual errors between 2 days and 35 days, with the lowest residuals observed in samples that have a TSD less than 6 days. This information can provide probative leads during an investigation of an illicit canine fighting event or an individual injury and also allow animal cruelty agencies to triage blood samples based on their TSD for downstream analyses. Full article