Journal of Biophotonics最新文献

The elasticity of the limbus is crucial for ocular health, yet it remains inadequately explored. This study employs acoustic radiation force optical coherence elastography (ARF-OCE) to evaluate the biomechanical properties of the limbus under varying intraocular pressures. The method was validated using a heterogeneous phantom and subsequently applied to ex vivo porcine limbus samples. Elastic wave velocity at specific locations within the limbus was calculated, and the corresponding Young's modulus values were obtained. Spatial elasticity distribution maps were generated by correlating Young's modulus values with their respective locations in the two-dimensional structural images. The results indicate that ARF-OCE enhances the understanding of limbus biomechanical behavior and holds potential for diagnosing regional variations caused by ocular diseases.

Multiphoton fluorescence microscopy excited with femtosecond pulses at high repetition rates, particularly in the range of 100's MHz to GHz, offers an alternative solution to suppress photoinduced damage to biological samples, for example, photobleaching. Here, we demonstrate the use of a U-Net-based deep-learning algorithm for suppressing the inherent shot noise of the two-photon fluorescence images excited with GHz femtosecond pulses. With the trained denoising neural network, the image quality of the representative two-photon fluorescence images of the biological samples is shown to be significantly improved. Moreover, for input raw images with even SNR reduced to −4.76 dB, the trained denoising network can recover the main image structure from noise floor with acceptable fidelity and spatial resolution. It is anticipated that the combination of GHz femtosecond pulses and deep-learning denoising algorithm can be a promising solution for eliminating the trade-off between photoinduced damage and image quality in nonlinear optical imaging platforms.

Low back pain (LBP) is the leading cause of disability worldwide, yet its quantitative and noninvasive assessment remains challenging. Considering that near-infrared spectroscopy (NIRS) became a promising noninvasive tool for monitoring muscle and cupping therapy could regulate muscle blood flow to relieve LBP, we attempted to incorporate cupping and hemodynamics monitoring in muscle tissue by NIRS to assess LBP. We collected 3-min NIRS recordings on 12 LBP patients and 12 healthy subjects before and after 20-min cupping. Initially, no significant hemodynamic differences were observed between the groups. After cupping, the concentration changes of oxy-hemoglobin (Δ[HbO₂]) in the emitter-detector channel parallel to spine unexpectedly exhibited that LBP was remarkably lower by approximately 67% compared with the controls. This study highlighted the potential of combining NIRS and cupping protocol as a quantitative assessment technique for LBP, also providing a new idea for clinical integration of novel optical assessment technologies.

Postoperative bleeding is the most significant complication of tonsillectomy. Regular monitoring of post-surgical wound healing in the pharynx is required. For this purpose, we propose endoscope-based non-invasive perfusion mapping and quantification. The combination of imaging photoplethysmography and image processing provides automated wound area selection and microcirculation characterization. In this feasibility study, we demonstrate the first results of the proposed approach to wound monitoring in clinical trial on eight patients after tonsillectomy. Combination of probe-based optical system and image processing algorithms can provide the valuable and consistent data on perfusion distribution. The quantitative microcirculation data obtained 1, 4, and 7 days after surgery are in good agreement with existing monitoring protocols.

Photobiomodulation therapy, as an emerging treatment modality, has been widely used in dentistry. However, reports on blue light therapy for oral cancer are scarce. This study investigated the effects of 457 and 475 nm LED irradiation on SCC-25 cells and explored the potential mechanisms underlying the impact of blue light. Both wavelengths were found to inhibit cell viability, induce oxidative stress, and cause cell cycle arrest without leading to cell death. Notably, the inhibitory effect of 457 nm blue light on cell proliferation was more sustained. Transcriptome sequencing was performed to explore the underlying mechanisms, revealing that blue light induced endoplasmic reticulum stress in SCC-25 cells, with 457 nm light showing a more pronounced effect. Moreover, 457 nm blue light upregulated the expression of the aryl hydrocarbon receptor pathway, indicating potential therapeutic prospects for the combined use of blue light and pharmacological agents.