Journal of biophotonics最新文献

Lyme disease (LD), caused by Borreliella burgdorferi, is the most common tick-borne illness in the United States, yet early-stage diagnosis remains challenging due to the limitations of current serological diagnostics. Raman spectroscopy (RS), paired with partial least squares discriminant analysis (PLS-DA), showed promise as an alternative diagnostic tool. Using RS, we analyzed 107 coded human blood samples (42 LD-positive and 65 LD-negative) obtained from the Lyme Disease Biobank. PLS-DA models showed nearly perfect internal validation performance with a sensitivity and specificity of 97.1% and 100.0%, respectively, indicating robust predictive capabilities. External validation of the developed chemometrics model with 80/20 training/validation split of all spectra gave true positive rates of 92.7% and 87.3% for serological positive and negative spectra, respectively. These findings highlight the potential of RS as a rapid and noninvasive diagnostic platform for LD, particularly when integrated with machine learning.

Jaundice due to excess bilirubin buildup in neonates remains an alarming problem, especially during the very first week of postnatal life. The common method of measuring total serum bilirubin (TSB) levels involves invasive blood testing, which is time-consuming and uncomfortable for neonates. While noninvasive transcutaneous bilirubinometers (TcB) are available, that often lack accuracy due to interference from other biological chromophores. This study aims to improve bilirubin assessment by developing a noninvasive system that uses diffuse reflectance spectroscopy and a novel algorithm accounting for chromophores like melanin and hemoglobin. Focusing on the sternum as the measurement site, spectra are collected from 285 newborns. Using the proposed algorithm, the bilirubin concentration is calculated at 450, 460, and 470 nm. Compared to TSB levels, the proposed method demonstrated strong accuracy with an average bias of -0.10 mg/dL and narrower limits of agreement of 4.85 mg/dL at 470 nm.

This article gives an overview of the most frequently used fluorescence-lifetime imaging (FLIM) techniques, their capabilities, and typical applications. Starting from a general introduction to fluorescence and phosphorescence lifetime, we will show that the fluorescence lifetime or, more accurately, the fluorescence decay function of a fluorophore is a direct indicator of the interaction with its molecular environment. FLIM is therefore more than a simple contrast technique in microscopy-it is a technique of molecular imaging. FLIM techniques can be classified into time-domain and frequency-domain techniques, analogue and photon counting techniques, and scanning and wide-field techniques. Starting from an overview of these general technical principles we will describe the features and peculiarities of the different FLIM techniques in use. An extended section is dedicated to TCSPC FLIM, addressing unique capabilities that make the technique especially interesting to FLIM of biological systems.

This study aimed to elucidate the response of B16F10 cells to blue light following infection with an empty adenoviral vector (Adv). Twenty-four hours post-infection, the B16F10 cells underwent phototherapy, and a range of cellular parameters were assessed, including cell viability, melanin content, cell cycle progression, reactive oxygen species (ROS) production, mitochondrial membrane potential (MMP), apoptosis, necrosis, lactate dehydrogenase (LDH) release, and autophagy. The findings indicated that Adv infection elevated melanin content and autophagy, resulting in G1 phase cell cycle arrest. In comparison to the control group, light-treated, Adv-infected cells exhibited reduced inhibition rates, LDH release, apoptosis, and necrosis, while MMP and ROS levels were elevated. The study concluded that although Adv, as a gene delivery vector in conjunction with light therapy, significantly modulated melanin content and autophagy. Moreover, while melanin's light absorption capacity mitigated MMP reduction, the resultant excitation molecules generated ROS, enhancing oxidative stress.

Keratoconus and other corneal ectatic disorders involve the degradation of collagen fibers, which compromises the corneal biomechanical properties. Ultraviolet-A (UVA) crosslinking has emerged as the primary treatment to slow down collagen degradation. This treatment is limited in both penetration depth and spatial precision, potentially leading to unwanted side effects. This study compares the changes in biomechanical properties of corneas crosslinked with UVA irradiation and a near-infrared femtosecond laser, using Brillouin microscopy. The biomechanical properties of the crosslinked regions were mapped in terms of Brillouin frequency shift in three dimensions. UVA crosslinking showed an average increase in Brillouin frequency shift of ~100 MHz. We demonstrate targeted spatial and axial corneal femtosecond crosslinking, with similar Brillouin frequency shift values to UVA in crosslinked regions.

Remote heart rate measurement is an increasingly concerned research field, usually using remote photoplethysmography to collect heart rate information through video data collection. However, in certain specific scenarios (such as low light conditions, intense lighting, and non-line-of-sight situations), traditional methods fail to capture image information effectively, that may lead to difficulty or inability in measuring heart rate. To address these limitations, this study proposes non-contact heart rate detection based on ghost imaging architecture. The mean absolute error between experimental measurements and reference true values is 4.24 bpm. Additionally, the bucket signals obtained by the ghost imaging system can be directly processed using digital signal processing techniques, thereby enhancing personal privacy protection.

Canine cancers are becoming increasingly significant due to their natural occurrence, similar to the spontaneous cancers in humans as well as their histological and biological similarities to human cancers. Several oral cancer types have been witnessed in dogs, based on the cell type from which the tumour originates. The type of oral tumour dictates severity of the disease, treatment options and prognoses. The current tissue-based Raman Spectroscopy (RS) study explores stratification of canine cancers. Raman spectra of histopathologically confirmed normal and oral tumour types namely Epulis, Spindle cell sarcoma (SCS), and Squamous cell carcinoma (SCC) were acquired using a Raman confocal microscope with 532 nm laser, pre-processed and multivariate analyses performed. PC-LDA achieved overall classification accuracy of > 70%. Thus, the present study evaluates potential of RS to identify the tumour type based on the identification of characteristic spectral features. Findings warrant large scale in vivo RS explorations in canine cancer subjects.

Low-level laser therapy (LLLT) is a non-invasive treatment that uses low-power lasers or light sources to stimulate biological responses. Previous studies focused on single-wavelength effects on hair growth in mice. In this study, we investigated dual-wavelength combinations to enhance hair regrowth. Using light-emitting diodes (LEDs) at 670, 680, 780, and 880 nm, we assessed the correlation between different wavelength pairs and hair regrowth after shaving in mice. Phototherapy was conducted over 14 days, with results analyzed through surface image analysis and histological examination. Our findings indicate that dual-wavelength therapy is superior to single-wavelength treatment and significantly more effective than the untreated control, demonstrating its potential for improved hair regrowth.

Photothermal therapy (PTT) offers a minimally invasive approach for cancer treatment, using light energy to selectively heat and destroy cancer cells. Success in PTT depends on efficient, stable, and biocompatible photothermal agents. This study investigates polypyrrole@gold nanocomposites (PPy@Au NCs) as photothermal agents combined with polarized polychromatic low-energy light (PPLEL) to target tumors and limit disease progression. In vivo experiments on Ehrlich carcinoma-bearing female Swiss albino mice demonstrated that PPy@Au NCs selectively accumulated in tumor tissue and, when activated by PPLEL, generated sufficient heat for effective tumor ablation. This approach enhanced treatment efficacy and presented a cost-effective solution due to the affordability of both the nanocomposite and light source. Histopathological analysis confirmed significant tumor reduction, suggesting that this synergistic combination offers a promising cancer treatment strategy. Findings support further research and potential clinical applications in photothermal cancer therapy.

The aim of the study is to compare the performance of surface-enhanced Raman spectroscopy (SERS) analysis of serum using a non-cooled detector (EnSpectr R785) and a high spectral resolution detector (Renishaw) in the task of discrimination between the patients with chronic heart failure and the patients with chronic obstructive pulmonary disease. The SERS-based solution of the classification problem demonstrates an insignificant relationship between the disease classification accuracy and detector quality (classification accuracy for the high-resolution setup is 0.84 and for the low-cost setup is 0.81). In the data recorded on Renishaw setup, the most significant bands are 611, 675, 720, 804, 1187, 1495, and 1847 cm^-1; for the EnSpectr setup-721, 1051, and 1665 cm^-1. The results have revealed equal discrimination capabilities in the EnSpectr and the Renishaw setups; however, the Renishaw setup has more prospects for identifying the spectral contribution of pathologically associated analytes.