Journal of Biophotonics最新文献

Phyllodes tumors (PTs) are rare breast stroma neoplasms, and their accurate identification at various stages is essential for personalized patient treatment. In this study, multiphoton microscopy (MPM) with two-photon excited fluorescence (TPEF) and second harmonic generation (SHG) imaging was used for label-free detection and differentiation of PTs and normal breast tissue. An automated image processing strategy was developed to quantify changes in collagen fiber morphology within the stroma and boundary of PTs, establishing optical diagnostic characteristics of PTs using MPM. The results demonstrated that MPM could be used for the detection of different stages of PTs, and the morphological alterations in collagen fibers could serve as critical indicators of PT malignancy, offering new insights for the diagnosis and grading of benign, borderline, and malignant PTs. It lays the groundwork for the future application of compact MPM for the rapid detection and diagnosis of PTs.

Laser-irradiation-assisted cell gene transfection is sterile and nontoxic, but the low transfection efficiency cannot meet the application requirements. To improve the efficiency, a temporal and spatial shaping method of a femtosecond laser is proposed. Using the time shaping method, we can segment the pulse into subpulses of varying energies and with a defined delay, thereby influencing the interaction between electrons and photons, ultimately enhancing transfection efficiency. The transfection efficiency is further improved by spatially shaping the laser pulse to extend the focusing beam's working distance and reduce the cell's sensitivity to the focal position. Through the characterization of the viability and transfection efficiency of HEK-293T cells, the method achieved efficient and active transfection, with a maximum transfection efficiency of 45.1% and a cell survival rate of 93.6%. This method provides key technical support for femtosecond laser transfection and promotes its further application in clinical practice.

A study of 355 nm laser with high pulse energy across various types of atherosclerotic lesion models is presented. The 355 nm laser pulses (10 ns) are delivered via a single fiber (600 μm diameter), and the ablation of calcified tissue, lipid tissue, and thrombus-like tissue are studied under varied laser fluence (40–70 mJ/mm²) and repetition rate (5–30 Hz). The contact and noncontact ablation processes of chicken tibia samples (calcified tissue) are compared at 60 mJ/mm² and 30 Hz, and the size of ablation particles is in the range of 0.1–1 μm. At the same repetition rate, the advancement rate of tricalcium phosphate samples reaches 150 μm/s at 70 mJ/mm². Calcified and lipid models demonstrate predictable increases in ablation with higher laser fluence and repetition rate. The fresh porcine blood clot samples exhibit high-quality ablation with good channel effect at 50 mJ/mm² and 30 Hz.

Optical biosensors are emerging as a promising technique for the sensitive and accurate detection of cancer biomarkers, enabling significant advancements in the field of early diagnosis. This study elaborates on the latest developments in optical biosensors designed for detecting cancer biomarkers, highlighting their vital significance in early cancer diagnosis. When combined with targeted nanoparticles, the bio-fluids can help in the molecular stage diagnosis of cancer. This enhances the discrimination of disease from the normal subjects drastically. The optical sensor methods that are involved in the disease diagnosis and imaging of cancer taken for the present review are surface plasmon resonance, localized surface plasmon resonance, fluorescence resonance energy transfer, surface-enhanced Raman spectroscopy and colorimetric sensing. The article meticulously describes the specific biomarkers and analytes that optical biosensors target. Beyond elucidating the underlying principles and applications, this article furnishes an overview of recent breakthroughs and emerging trends in the field. This encompasses the evolution of innovative nanomaterials and nanostructures designed to augment sensitivity and the incorporation of microfluidics for facilitating point-of-care testing, thereby charting a course towards prospective advancements.

Ischemic stroke (IS) is characterized by the sudden interruption of blood supply to the brain, resulting in neurological impairments and even mortality. Photoacoustic computed tomography (PACT) integrates the high contrast of optical imaging and the penetration of ultrasound imaging, enabling non-invasive IS evaluation. However, the image reconstruction quality significantly affects the oxyhemoglobin saturation (sO₂) estimation. This study investigates a model-based with total variation minimized by augmented Lagrangian and alternating direction (MB-TVAL3) approach and compared it with the widely used back-projection (BP) and delay-and-sum (DAS) algorithms. Both simulations and in vivo experiments are conducted to validate the performance of the MB-TVAL3 algorithm, showing a higher sO₂ estimation accuracy and sensitivity in detecting infarct area compared to BP and DAS. The findings of this study emphasize the impact of acoustic inverse problem on the accuracy of sO₂ estimation and the proposed approach offers valuable support for IS evaluation and cerebrovascular diagnosis.