Journal of biophotonics最新文献

Glioma is the most common brain neoplasm that features aggressive behavior with a dismal prognosis. Isocitrate dehydrogenase (IDH) gene mutation in glioma is an early genetic event in gliomagenesis that occurs in virtually every tumor cell and can cause profound metabolic changes. In this manuscript, we report for the first time the analysis of Raman optical signatures of IDH genotypes for human glioma using visible resonance Raman (VRR) spectroscopy. We demonstrated that VRR is a rapid, label-free, and objective method as an alternative to the existing methods for the rapid intraoperative determination of IDH mutation status with high accuracy. This study shows AI-assisted VRR has the potential to provide a new optical molecular biomarker and perform early diagnosis of glioma, which is of great importance for current guiding surgical strategies and even for targeting in situ therapies in the future.

Introduction: With their noninvasive capabilities for molecular-level analysis of biological tissues and cells, Raman spectroscopy and microscopy have become important tools in medicine and medical diagnostics.

Methods: In this work, we describe a reliable and repeatable technique for Raman spectroscopic profiling of human neutrophils in peripheral blood smears. 1200 single-cell spectra from 12 healthy donors were obtained using Raman microscopy, and the results showed consistent spectral features of key biomolecules such as proteins, nucleic acids, carotenoids, and cytochrome c.

Results: We used t-distributed stochastic neighbor embedding and principal component analysis to assess interindividual variability; both techniques showed minimal spectral divergence between donors and high reproducibility. This study lays the methodological groundwork for upcoming Raman microscopy applications enabling non-invasive assessment of immune cell states in health and disease.

Conclusion: Our results demonstrate the potential of Raman microscopy in clinical diagnostics, specifically for tracking the metabolic states of cells.

Super-resolution microscopy (SRM) has exerted a pivotal influence on virology by surpassing the diffraction limits of conventional optical microscopy, enabling unprecedented visualization of viral structures and dynamics. Techniques such as stimulated emission depletion, photoactivated localization microscopy, stochastic optical reconstruction microscopy, and structured illumination microscopy facilitate nanoscale imaging of viruses, providing critical insights into the viral life cycle and virus-host interactions. We examine the principles and advancements in SRM techniques and their applications in virology. We discuss the development and selection of fluorescent probes, highlighting specific labeling methods. Key applications of SRM are illustrated through case studies of viruses such as influenza, HIV, and SARS-CoV-2, demonstrating the technology's impact on understanding viral mechanisms. We also explore future developments in SRM, including enhanced spatial and temporal resolution, and integration with technologies such as single-molecule imaging and fluorescence resonance energy transfer, positioning SRM as a pivotal tool for advancing viral research and therapeutic development.

Vulvar intraepithelial neoplasia (VIN) is increasing in prevalence, yet screening options remain limited and existing diagnostic methods show low accuracy. This study evaluates infrared thermal imaging as an alternative screening approach for VIN detection. We analyzed thermal images from 51 patients with histopathologically confirmed VIN, captured using a FLIR A400 thermal camera. Temperature distributions of healthy vulvar tissue were first characterized to establish baseline values. Thermal features of VIN lesions were then extracted and optimized using principal component analysis (PCA). Three machine learning models-support vector machine (SVM), random forest (RF), and linear discriminant analysis (LDA)-were trained and evaluated for VIN diagnosis. SVM demonstrated the best performance with an F1 score of 75% and accuracy of 74.19%. These findings suggest that machine learning-based infrared thermography shows promise as a non-invasive screening tool for VIN detection.

We present a tunable polarization imaging system (TPS) incorporating a liquid crystal polarization grating (LCPG) and a quarter-wave plate (QWP). TPS overcomes low diffraction efficiency and insufficient flexibility in polarimetric imaging, leveraging the LCPG's high diffraction efficiency (> 98%) and polarization control via LCPG-QWP combination. Using the TPS, we conducted comparative experiments on five types of pathological tissue sections, employing six types of polarized light alongside unpolarized light (serving as the control group), and acquired polarization images. Furthermore, we applied multidimensional data analysis methods to analyze and compare the obtained polarization images. The results show that polarized light significantly enhances texture contrast in diseased tissues, achieving a 284% increase compared to acquisitions using unpolarized light, while enabling robust discrimination between benign and malignant tissues. TPS, characterized by its high efficiency, compact design, and compatibility with existing equipment, shows great potential for label-free, pathological-section-based early cancer diagnosis.

Seborrheic keratosis is a common benign skin tumor. None of the current conventional testing techniques can assess the mechanical properties of the tissue, such as hardness, elasticity and viscoelasticity. In this study, we investigated the morphological and elastic properties of seborrheic keratosis (SK), a common benign skin tumor, using optical coherence elastography (OCE). We found that the OCE technique was able to distinguish SK tissue from normal tissue. In addition, by measuring skin elasticity, it was possible to identify SK lesions with different clinical types and dermoscopic patterns of presentation. As a non-invasive quantitative tool, OCE demonstrates significant potential in the clinical diagnosis and assessment of skin aging diseases, providing objective evaluations based on elasticity.

Effective osteogenic differentiation of human dental pulp stem cells (hDPSCs) is critical for regenerative applications. This study examined the synergistic effects of 810 nm near-infrared photobiomodulation (PBM) and allogeneic fibrin serum (AFS) on hDPSC differentiation and tissue regeneration. Cells cultured with 10% fetal bovine serum or 5% AFS were irradiated with PBM at 71 or 142 mJ/cm². Osteogenesis was assessed by qRT-PCR, Alizarin Red S staining with semi-quantitative image analysis, and histological evaluation of transplanted constructs in immunocompromised mice. PBM alone transiently suppressed early osteogenic markers on Day 7. By Day 14, combined treatment with AFS and 142 mJ/cm² PBM significantly upregulated ALP, COL1, RUNX2, OCN, and RANKL, and enhanced matrix mineralization. In vivo, 8-week constructs pretreated with PBM and AFS showed organized architecture and early mineralization. These findings support PBM-AFS synergy, potentially involving TGF-β1 signaling, as a promising xeno-free approach for bone and dental tissue regeneration.

Longitudinal monitoring of actinic keratosis (AK) is a part of patient management, scientific studies, and the development of new treatment strategies. Dynamic optical coherence tomography (D-OCT), an imaging method that enables noninvasive assessment of microvasculature, in conjunction with automated quantitative analysis, shows promise as an objective and robust method for monitoring AKs. Critical to quantitative longitudinal assessments is a dataset in which good-quality images are available at all time points. Yet, to date, few resources exist to train clinical researchers on how to ensure robust D-OCT data collection. In this study, we identify hallmarks of poor image quality to guide data curation and avoid biasing study results. We highlight strategies for imaging lesions with significant hyperkeratosis. Finally, we discuss characteristic features present in D-OCT images of AK that may complicate quantitative analysis. We hope that this work will facilitate the use of D-OCT in the objective longitudinal assessment of AK.

The optical Kerr effect (OKE) spectroscopy is a powerful technique to study ultrafast dynamics of a material's response to an optical field. In this study, we investigated OKE in Alzheimer's disease (AD) and normal human brain tissues from the hippocampus and Brodmann areas 9 and 17. The Kerr signals from both AD and normal samples exhibited a distinct double-peak profile, corresponding to the electronic and plasma mechanisms. Analysis of plasma relaxation and dielectric response times revealed that conductivity in the AD hippocampus was approximately 46%-61% higher than in normal tissue, due to an increase in structural inhomogeneity, which may arise from tau and amyloid-beta (Aβ) protein accumulation and elevated water content. Overall, the mean conductivity across the three regions was 38% higher in AD compared to normal tissue. These findings demonstrate that OKE can provide valuable information on underlying molecular mechanisms of the brain that occur on ultrafast timescale.