Dissociation Kinetics and Antimicrobial Activity of Ofloxacin Antibiotic in Artificial Tears Via 1H-NMR, Raman, and UV-Vis Spectroscopic Analysis.

Introduction: The hydrogen-bonded networks play a significant role in influencing several physicochemical properties of ofloxacin in artificial tears (ATs), including density, pH, viscosity, and self-diffusion coefficients. The activities of the ofloxacin antibiotic with Ats mixtures are not solely determined by their concentration but are also influenced by the strength of the hydrogen bonding network which highlight the importance of considering factors such as excessive tear production and dry eye conditions when formulating appropriate dosages of ofloxacin antibiotics for eye drops. Objectives: Investigating the physicochemical properties of ofloxacin-ATs mixtures, which serve as a model for understanding the impact of hydrogen bonding on the antimicrobial activity of ofloxacin antibiotic eye drops. Determine the antimicrobial activities of the ofloxacin-Ats mixture with different concentration of ofloxacin. Methods: The ofloxacin-ATs mixtures were analyzed using 1H-NMR, Raman, and UV-Vis spectroscopies, with variation of ofloxacin concentration to study its dissociation kinetics in ATs, mimicking its behavior in human eye tears. The investigation includes comprehensive analysis of 1H-NMR spectral data, self-diffusion coefficients, Raman spectroscopy, UV-Vis spectroscopy, liquid viscosity, and acidity, providing a comprehensive assessment of the physicochemical properties. Results: Analysis of NMR chemical shifts, linewidths, and self-diffusion coefficient curves reveals distinct patterns, with peaks or minima observed around 0.6 ofloxacin mole fraction dissociated in ATs, indicating a strong correlation with the hydrogen bonding network. Additionally, the pH data exhibits a similar trend to viscosity, suggesting an influence of the hydrogen bonding network on protonic ion concentrations. Antibacterial activity of the ofloxacin-ATs mixtures is evaluated through growth rate analysis against Salmonella typhimurium, considering varying concentrations with mole fractions of 0.1, 0.4, 0.6, 0.8, and 0.9. Conclusions: The antibiotic-ATs mixture with a mole fraction of 0.6 ofloxacin exhibited lower activity compared to mixtures with mole fractions of 0.1 and 0.4, despite its lower concentration. The activities of the mixtures are not solely dependent on concentration but are also influenced by the strength of the hydrogen bonding network. These findings emphasize the importance of considering tear over-secretion and dry eye problems when designing appropriate doses of ofloxacin antibiotics for eye drop formulations.

CARS Imaging Advances Early Diagnosis of Cardiac Manifestation of Fabry Disease.

Vibrational spectroscopy can detect characteristic biomolecular signatures and thus has the potential to support diagnostics. Fabry disease (FD) is a lipid disorder disease that leads to accumulations of globotriaosylceramide in different organs, including the heart, which is particularly critical for the patient's prognosis. Effective treatment options are available if initiated at early disease stages, but many patients are late- or under-diagnosed. Since Coherent anti-Stokes Raman (CARS) imaging has a high sensitivity for lipid/protein shifts, we applied CARS as a diagnostic tool to assess cardiac FD manifestation in an FD mouse model. CARS measurements combined with multivariate data analysis, including image preprocessing followed by image clustering and data-driven modeling, allowed for differentiation between FD and control groups. Indeed, CARS identified shifts of lipid/protein content between the two groups in cardiac tissue visually and by subsequent automated bioinformatic discrimination with a mean sensitivity of 90-96%. Of note, this genotype differentiation was successful at a very early time point during disease development when only kidneys are visibly affected by globotriaosylceramide depositions. Altogether, the sensitivity of CARS combined with multivariate analysis allows reliable diagnostic support of early FD organ manifestation and may thus improve diagnosis, prognosis, and possibly therapeutic monitoring of FD.

Fast and Noninvasive Diagnosis of Cervical Cancer by Coherent Anti-Stokes Raman Scattering.

Cervical cancer is the fourth most common cancer in women worldwide, and early detection of its precancerous lesions can decrease mortality. Cytopathology, HPV testing, and histopathology are the most commonly used tools in clinical practice. However, these methods suffer from many limitations such as subjectivity, cost, and time. Therefore, there is an unmet clinical need to develop new noninvasive methods for the early detection of cervical cancer. Here, a novel noninvasive, fast, and label-free approach with high accuracy is presented using liquid-based cytology Pap smears. CARS and SHG/TPF imaging was performed at one wavenumber on the Pap smears from patients with specimens negative for intraepithelial lesions or malignancy (NILM), and low-grade (LSIL) and high-grade (HSIL) squamous intraepithelial lesions. The normal, LSIL, and HSIL cells were selected on the basis of the ratio of the nucleus to the cytoplasm and cell morphology. Raman spectral imaging of single cells from the same smears was also performed to provide integral biochemical information of cells. Deep convolutional neural networks (DCNNs) were trained independently with CARS, SHG/TPF, and Raman images, taking into account both morphotextural and spectral information. DCNNs based on CARS, SHG/TPF, or Raman images have discriminated between normal and cancerous Pap smears with 100% accuracy. These results demonstrate that CARS/SHG/TPF microscopy has a prospective use as a label-free imaging technique for the fast screening of a large number of cells in cytopathological samples.