Biology subjects

Glasl, S.

Publications and source records attributed to Glasl, S..

4 recordsLinked to original sources

bioRxiv2024

Non-invasive optoacoustic imaging visualizes exercise-induced dermal revascularization in obese mice

Microcirculatory dysfunction in dermal (dWAT) and subcutaneous white adipose tissue (scWAT) of obese humans may predict cardio-metabolic disease progression. In-vivo visualization and monitoring of microvascular remodeling in these tissues remains challenging. We compared performance of multi-spectral optoacoustic tomography (MSOT) and raster-scanning optoacoustic mesoscopy (RSOM) in visualizing lipid and hemoglobin contrast in scWAT and dWAT of diet-induced obese (DIO) mice undergoing voluntary wheel running. MSOT quantitatively visualized lipid and hemoglobin contrast in fat depots at early stages of DIO. RSOM precisely visualizes microvasculature with quantitative readouts of skin layer thickness and vascular density in dWAT and dermis. Combination of MSOT and RSOM resolved exercise-induced morphological changes in microvasculature density, tissue oxygen saturation, lipid and blood volume content in dWAT and scWAT. Combination of MSOT and RSOM precisely monitor microcirculatory dysfunction and intervention response in dWAT and scWAT of DIO mice. Our findings lay out the foundation for future clinical studies using optoacoustic-derived vascular readouts from adipose tissues as a biomarker for monitoring microcirculatory function in cardio-metabolic disease.

bioengineering↗

bioRxiv2023

Structure-function relationships of mucociliary clearance in the human airways

Mucociliary clearance is a vital defense mechanism of the human airways, protecting against harmful particles and infections. When this process fails, it contributes to respiratory diseases like chronic obstructive pulmonary disease (COPD) and asthma. While advances in single-cell transcriptomics have revealed the complexity of airway composition, much of what we know about how airway structure impacts clearance relies on animal studies. This limits our ability to create accurate human-based models of airway diseases. Here we show that the airways in female rats and in humans exhibit species-specific differences in the distribution of ciliated and secretory cells as well as in ciliary beat, resulting in significantly higher clearance effectiveness in humans. We further reveal that standard lab-grown cultures exhibit lower clearance effectiveness compared to human airways, and we identify the underlying structural differences. By combining diverse experiments and physics-based modeling, we establish universal benchmarks to assess human airway function, interpret preclinical models, and better understand disease-specific impairments in mucociliary clearance.

biophysics↗

bioRxiv2022

Non-invasive in-blood glucose sensing

Non-invasive glucose monitoring (NIGM) is increasingly considered as an alternative to finger pricking for blood glucose assessment and management of diabetes in insulin-dependent patients, due to the pain, risk of infection, and inadequacy of finger pricking for frequent measurements. Nevertheless, current NIGM techniques do not measure glucose in blood, but rely on indirect bulk measurement of glucose in the interstitial fluid, where glucose is less concentrated, diluted in a generally unknown volume, and appears in a delayed fashion relative to blood glucose, impairing NIGM accuracy. We introduce a new biosensor, termed Depth-gated mid-InfraRed Optoacoustic Sensor (DIROS), which offers for the first time non-invasive glucose detection directly in blood, while simultaneously rejecting contributions from the metabolically inactive stratum corneum and other superficial skin layers. This unique ability is achieved by time-gating mid-infrared optoacoustic signals to enable glucose readings from depth-selective localization in the microvasculature of the skin. In measurements of mice in vivo, DIROS revealed marked accuracy improvement over conventional bulk-tissue glucose measurements. We showcase how skin rejection and signal localization are essential for improving the NIGM accuracy, and discuss key results and how DIROS offers a holistic approach to address limitations of current NIGM methods, with high translation potential.

bioengineering↗

bioRxiv2021

Frequency Comb Optoacoustic Tomography

Optoacoustics (OA) is overwhelmingly implemented in the Time Domain (TD) to achieve a high Signal-to-Noise-Ratio (SNR). Implementations in the Frequency Domain (FD) have been proposed, but have not offered competitive advantages over TD methods to reach high dissemination. It is therefore commonly believed that the TD represents the optimal way of performing optoacoustics. Here, we introduce a novel optoacoustic concept based on frequency comb and theoretically demonstrate its superiority to the TD. Then, using recent advances in laser diode illumination, we launch Frequency Comb Optoacoustic Tomography (FCOT), at multiple wavelengths, and experimentally demonstrate its advantages over TD methods in phantoms and in-vivo. We demonstrate that FCOT optimizes the SNR of spectral measurements over TD methods by benefiting from signal acquisition in the TD and processing in the FD, and that it reaches the fastest multi-spectral operation ever demonstrated in optoacoustics while reducing performance compromises present in TD systems.

biophysics↗