Journal of biophotonics最新文献

Squamous cell carcinoma (SCC), a common epithelial cancer, requires early identification for treatment. Our innovative multimodal microscopic system allows bright-field microscopy, autofluorescence microscopy, quantitative phase microscopy (QPM) using the transport of intensity equation (TIE), and autofluorescence spectroscopy from a single field of view (FOV). This integrated method permits morphological and biochemical analysis of unstained tissue sections without labeling. Autofluorescence imaging in well-differentiated SCC tissue was distinct from normal tissue. The same field of view autofluorescence spectra showed a considerable increase in emission intensity at 550 nm, indicating pathological changes. It eliminates the need for dyes by using endogenous fluorophores to contrast healthy, dysplasia, and cancerous oral tissues. The autofluorescence spectroscopy method instantly collects emission spectra, quantifying metabolic changes linked with cancer progression. QPM improves refractive index distribution mapping sensitivity, enhancing spectral data for label-free diagnosis.

Accurate differentiation between intrahepatic cholangiocarcinoma (ICC) and hepatocellular carcinoma (HCC) remains challenging due to overlapping imaging features. We propose a hyperspectral imaging (HSI)-based diagnostic framework using a lightweight Spectral-MLP network for label-free tumor classification. Seventy-nine liver specimens were analyzed after spectral calibration, noise-band removal, and normalization within 450-900 nm. Spectral analysis revealed distinct differences in hemoglobin-related bands (540-580 nm) and lipid/water absorption regions (760-850 nm), corresponding to vascular and stromal variations between ICC and HCC. The proposed Spectral-MLP achieved 93.6% accuracy, 93.1% sensitivity, 94.0% specificity, and an AUC of 0.965, comparable to deeper models but with higher efficiency. These findings demonstrate that hyperspectral data combined with a simple neural network can effectively distinguish ICC from HCC and suggest that the lightweight Spectral-MLP framework has the potential to provide interpretable, real-time, and clinically deployable decision support for optical pathological diagnosis.

Photobiomodulation shows promise in modulating complex mechanisms of chronic wound healing. Current photobiomodulation devices remain costly and technically demanding. Therefore, this study reports the development of a simple, portable and operationally and easy-to-use LED-based photobiomodulation device for the treatment of skin lesions. The design and operating parameters confirmed the device's safety and energy efficiency. In vitro LED irradiation on fibroblasts increased cell viability, without inducing proliferation. The treatment prevented cellular shrinkage, as evidenced by a higher number of smaller cells in the control group. Irradiation also enhanced cell migration at 72 and 96 h after treatment. Significantly increased adhesion to fibronectin was observed in the irradiated group, with no effect on type I collagen adhesion. Nevertheless, no significant differences were observed in the proportion of cells in the sub-G0/G1, G0/G1, S, and G2/M phases of the cell cycle. In conclusion, the LED device provides a reliable source of electromagnetic stimulation with healing effects.

Extracellular vesicles (EVs) are critical in cellular communication and pathological biomarkers. Post-translationally deiminated/citrullinated proteins are reported in EV cargoes by LC-MS/MS but it is unknown in which EV sub-types they are exported, as part of EVs' intraluminal cargo or on the EV surface. Here, dSTORM super-resolution microscopy is used to co-localise total citrullinated proteins (pan-Cit), and citrullinated histone H3 (CitH3) to EV subtypes of three cancer cell lines, captured by tetraspanin trio (TT) or phosphatidylserine (PS). Permeabilised and non-permeabilised EVs are analysed with a Bayesian framework using beta-distributed posteriors for binomial outcomes. Pan-Cit and CitH3 labelling is confirmed in EVs as intraluminal cargo and on the EV surface, with higher levels detected in the permeabilized EVs. Pan-Cit staining is higher in TT-bound EVs, but CitH3 staining higher in PS-bound EVs. This study expands the landscape of EV-associated post-translational modifications with translational potential for EV-citrullinome based liquid biopsy tools.

Melasma is a common pigmentary disorder involving melanin deposition and structural alterations. Current diagnostic methods mainly target pigmentation and lack real-time assessment of histopathology. This study proposes a noninvasive, quantitative evaluation of basement membrane (BM) disruption in melasma using optical coherence tomography (OCT) with deep learning. Cross-sectional skin images were generated by attenuation coefficient (AC) mapping of OCT B-scans. An improved Unet (Res-Att-Unet), integrating residual and attention modules, was developed for BM segmentation. AC mapping enhanced image contrast, yielding superior BM segmentation over conventional OCT. The proposed model achieved an accuracy of 81.4%, F1-score of 83.8%, and IoU of 72.1%. BM loss in melasma (66.0% ± 19.8%) was significantly higher than in perilesional skin (47.2% ± 18.5%, p < 0.001). Longitudinal monitoring revealed a significant BM recovery after tranexamic acid (TXA) treatment. These results indicate that our proposed method can be potentially used in clinic for in vivo BM assessment, aiding in melasma diagnosis.

We performed a multimodal characterisation of self-assembled fibrillar aggregates formed by the residue 87-114 fragment of the white-tailed deer (WTD) prion protein (PrP), a disease-relevant region implicated in the structural conversion and transmission of chronic wasting disease (CWD) in cervids. Using an integrated experimental platform combining plasmon-enhanced bright-field microscopy, label-free surface-enhanced Raman spectroscopy (SERS), and Thioflavin T staining, we probed peptide aggregation in solution under ambient conditions. Nanostructured gold films on dielectric fused silica supports served as dual-purpose plasmonic substrates for imaging and SERS. We observed a transition from dispersed states to well-defined fibrillar networks, accompanied by spectral evolution in key backbone-sensitive SERS bands. These results establish the amide III region and tryptophan vibrational features as indicators of fibrillar architecture in SERS assays and offer new insights into the aggregation behavior of amyloidogenic sequences involved in CWD susceptibility.

Bacterial detection and identification are crucial tasks in today's world due to increasing casualties and severity caused by bacteria in hospital-acquired infections, food-borne infections, etc. This warrants an urgent need for rapid detection and identification of different bacterial strains. Fluorescence spectroscopy is a widely used technique for bacteria characterization owing to its high sensitivity, real-time, and simple measurement capabilities. In this work, fluorescence excitation spectra of 200 bacteria isolates belonging to eight different species were acquired under identical conditions with 25 isolates per species. The fluorescence excitation spectra were subjected to spectral deconvolution to extract four Gaussian components viz., tryptophan in protein under buried and exposed conditions, nucleic acids and anthranilic acid. Linear discriminant analysis applied to normalized fluorescence excitation spectra of 200 samples classified the bacterial strains with 100% accuracy using leave-one-out cross-validation.

Current research has shown that terahertz (THz) waves can induce some bioeffects on certain human tumor cells. These effects are significant for potential applications in future tumor treatments. However, there are limited reports on the research advancements in this field, likely due to the scarcity of powerful THz sources. Here, we preliminarily report biological effects on breast cancer and melanoma cells using a powerful THz source at 2.88 THz from a THz free-electron laser. We observed obvious morphological changes, especially the early apoptotic phenomena, in both cancer cells. Flow cytometry results further confirmed that some cancer cells had undergone early apoptosis. An evaluation of the thermal effects suggests that the apoptosis observed in both cancer cells could be mainly attributed to the non-thermal effects induced by the strong THz waves. Our findings indicate the potential for utilizing strong THz waves in non-inflammatory cancer treatment in the future.

A novel optomechanical biosensor architecture integrating an optomechanical racetrack-cantilever biosensor with a flexible cantilever is designed for simultaneous detection of chemical and cellular analytes. Pressure loads induced by glucose, dopamine, and MCF-7 cancer cells were modeled as mechanical deflections transduced into resonance wavelength shifts. Finite element simulations in ANSYS and COMSOL were validated against analytical beam theory with deviations below 1%. Distinct resonance signatures were observed for chemical and cellular analytes, demonstrating the capacity for analyte discrimination. PDMS cantilevers exhibited mean sensitivities of approximately 1.69 pm/kPa and maximum responses of 5.34 pm/kPa, whereas SiO₂ devices showed negligible sensitivity. These results demonstrate, through finite-element simulations and analytical modeling, the proof-of-concept operation of a racetrack-cantilever optomechanical biosensor. The study highlights key trends and limitations rather than providing an exhaustive experimental explanation, thereby offering a design foundation for future fabrication and validation.

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.