Conference Agenda

Calcific aortic valve disease is the third most common cardiovascular disorder worldwide, with surgical aortic valve replacement and transcatheter aortic valve implantation being the only therapeutic options. In this study, porcine pericardium—used for biological prostheses in over 90% of surgical valve replacements—was analyzed using polarization-sensitive optical coherence tomography (PS-OCT). The aim was to verify thickness measurements and visualize fiber orientation and stratification in the extracellular matrix.

Native and glutaraldehyde-fixed pericardium samples were examined with PS-OCT to determine tissue thickness and elastin fiber orientation. This non-destructive 3D imaging technique enables fast, non-invasive assessment of layered tissue structure based on backscattering intensity. The characteristic three-layer stratification observed in PS-OCT evaluation was confirmed through corresponding histological sections using Elastica staining.

Thickness measurements showed good agreement between PS-OCT and histology, with deviations of 2.56% for native tissue (194.69 µm vs. 189.70 µm) and 15.49 % for glutaraldehyde-fixed tissue (329.26 µm vs. 278.34 µm). The larger deviation in fixed samples is primarily attributed to tissue shrinkage induced by glutaraldehyde fixation and assumptions regarding refractive index. In conclusion, PS-OCT provides a precise, non-invasive alternative for monitoring structural and pathological changes in valve biomaterials, offering potential for improving material fabrication and understanding degeneration processes in pericardial valve prostheses.

Optical coherence tomography (OCT) is a promising tool for non-invasive middle ear diagnostics as it provides volumetric structural and functional information. An additional contrast can be achieved by analyzing the depth-resolved polarization changes within the tissue, thus resolving the microstructure which is otherwise indiscernible in intensity-based OCT images. Here, we apply a new otoscope-based polarization-sensitive OCT device to image the birefringent layers of the human tympanic membrane. Based on a differential reconstruction of the depth-resolved retardation and optic axis orientation, the layered structure of the lamina propria is revealed in vivo for the first time. In the future, applying PS-OCT for diagnostic purposes might improve the assessment of pathologic alterations of the eardrum.

We present flexible hydrogel-based biosensors for non-invasive monitoring of glucose and pH in sweat using two independently functionalized hydrogel systems. The hydrogels are functionalized with 3-aminophenylboronic acid (3-APBA) combined with the tertiary amine N-(3-(dimethylamino)propyl)acrylamide (DMAPAA) for glucose sensing, and methacrylic acid (MAA) for pH sensing. Analyte interactions induce reversible volumetric swelling proportional to concentration. Swelling is characterized by gravimetric analysis, whereas localized plasmon-based spectral shifts from UV-photoreduced gold nanostructures were detected by transmission spectroscopy. Glucose-sensitive hydrogels show a monotonic mass increase (0-10 mM), with ~5.3% increase at low concentrations (0-2.5 mM) and saturation at higher levels, accompanied by a red shift. pH-sensitive hydrogels demonstrate up to 145% mass increase when pH is tuned between 4 to 9 with a corresponding blue shift due to swelling-induced interparticle spacing changes and refractive index reduction. Both systems demonstrate reversible and stable cyclic behaviour. This dual-mode hydrogel platform enables sensitive, reversible, and scalable wearable biosensing for continuous health monitoring.

Biological fluids and biogases are complex matrices that require advanced sensing strategies for reliable characterization of both the medium and trace contaminants, ideally with a single platform. In this work, we investigate quartz tuning forks (QTFs) as multi-parametric sensors capable of probing both matrix properties and specific analytes. The resonance characteristics of the QTF were related to the surrounding physical properties of the fluid, while laser-textured, blackened QTFs enable their use as infrared photodetectors for tunable diode laser spectroscopic analysis of trace amounts in complex matrices.

Polymeric beads are established tools in diagnostic assays for biofluid analysis, serving as capture or reporter particles in formats such as latex agglutination tests and strip-based immunoassays. For these dispersed targets, there is growing interest in novel readout strategies that can improve sensitivity, quantification, and experimental simplicity beyond conventional approaches. In this context, we present a computational study of the thermoelastic photoacoustic response of suspended polymeric beads under pulsed mid-infrared excitation. The model considers 10 µm polymeric beads dispersed in an aqueous medium under ambient conditions, examining how pulse-driven heating, thermal relaxation, and bead expansion affect the generated pressure response. Furthermore, the analysis addresses the specific dependence of the photoacoustic signal on bead concentration and the physical mechanisms governing acoustic generation in the surrounding fluid. Ultimately, this work aims to assess the feasibility and sensitivity of this approach while identifying key governing parameters, thereby supporting the development of robust mid-IR photoacoustic readout methods for polymer-based diagnostic platforms.

This work demonstrates quantitative measurement of laser-induced

photothermal heating in magnetic nanoparticle (MNP) clusters using nitrogen-

vacancy (NV)-center-based widefield thermometry in a diamond-membrane

quantum microscope. By exploiting the temperature dependence of the NV

zero-field splitting, we obtain spatially resolved thermal maps and monitor heat-

ing and thermal relaxation dynamics in real time. The method enables non-

invasive temperature tracking over a 100 x 100 um field of view with sub-second

temporal resolution. These results highlight the potential of NV-based widefield

microscopy for studying nanoscale thermodynamics and optimizing biomedical

photothermal and hyperthermia processes.