Biology subjects

Leartprapun, N.

Publications and source records attributed to Leartprapun, N..

4 recordsLinked to original sources

bioRxiv2025

Valve endothelial monolayer fissuring via RhoA activity induces 3D calcific aortic valve lesion emergence as revealed by a longitudinal live-imaging platform

Calcific aortic valve disease (CAVD) is a degenerative disease with wide prevalence in the aging population and a low survival rate after onset of symptoms, yet there are no effective pharmacological treatments. Many patients present to the clinic with symptoms at end-stages of CAVD, when the disease may be irreversible. The ability to identify and live-trace calcific lesion emergence in-vivo would allow for the identification of disease biomarkers and discovery of therapeutic targets at earlier, more treatable stages. In this work, we establish a new multimodal in-vitro CAVD platform consisting of lineage traced-VEC and VIC cells in a 3D model combined with live optical coherence and fluorescence microscopy to unravel VEC, VIC, and matrix transitional events during calcific lesion formation. We discover that fissuring of the endothelial monolayer combined with the formation of dense aggregates in adjacent regions is a key biomarker of the onset of lesion formation. This coincides with the formation of dense VIC and ECM conglomerates under endothelial aggregates, an additional biomarker of pathogenesis. Further, we discover that fibrotic tissue compaction is correlated with but not necessary for lesion formation. Additionally, we identify RhoA activation in disease-treated samples. We demonstrate that RhoA inhibition through ROCK, but not Rac1 inhibition, prevents delamination of the endothelial monolayer, fibrotic remodeling, and emergence of calcific lesions. Together, this work establishes a new longitudinal live-imaging platform that identifies emergent cell and matrix biological signatures of CAVD onset and enables the evaluation of therapeutic interventions. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=64 SRC="FIGDIR/small/660489v1_ufig1.gif" ALT="Figure 1"> View larger version (24K): org.highwire.dtl.DTLVardef@dc378org.highwire.dtl.DTLVardef@19c37d5org.highwire.dtl.DTLVardef@11581c6org.highwire.dtl.DTLVardef@fb0a6a_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2024

Laser Speckle Particle Sizer (SPARSE) Informs the Size Distribution of Tissue Granularities

Particle sizing of biomaterials and tissues holds profound implications across diverse industrial and clinical disciplines. Conventional approaches such as dynamic light scattering (DLS) are restricted to dilute liquids, and unable to assess particle size distribution in intact, untampered biomaterials and tissues in their native state. Here, we introduce the laser Speckle PARticle SizEr (SPARSE), which leverages the size-dependent attributes of polarized back-scattered laser speckle to characterize the average radius of a continuum of endogenous scattering particles, in the 10nm-10m range, in biological fluids and soft tissues in their native state. The SPARSE approach exploits cross- and co-polarized attributes of spatial and temporal laser speckle intensity fluctuations to quantify the average particle size in various specimens, including polystyrene microspheres, milk, whole blood specimens, and intact soft tissues, without prior knowledge or explicit account of refractive index and scattering concentrations. Through scanning the laser beam across the tissue surface, we establish the capability of SPARSE to evaluate a spatial map of heterogenous scattering particle sizes with a resolution of a few 10s of m that closely mirrors histopathological microstructures in benign and carcinoma breast tissue specimens. By enabling the size characterization of intact tissues and biomaterials across a continuum of granularities, non-destructively in native specimens, SPARSE opens substantial opportunities for quality control in industrial applications, drug development, and advanced clinical diagnostics.

biophysics↗

bioRxiv2023

Speckle rheological spectroscopy reveals wideband viscoelastic spectra of biological tissues

Mechanical transformation of tissue is not merely a symptom but a decisive driver in pathological processes. Comprising intricate network of cells, fibrillar proteins, and interstitial fluid, tissues exhibit distinct solid- (elastic) and liquid-like (viscous) behaviours that span a wide band of frequencies. Yet, characterization of wideband viscoelastic behaviour in whole tissue has not been investigated, leaving a vast knowledge gap in the higher frequency range that is linked to fundamental intracellular processes and microstructural dynamics. Here, we present wideband Speckle rHEologicAl spectRoScopy (SHEARS) to address this need. We demonstrate, for the first time, analysis of frequency-dependent elastic and viscous moduli up to the sub-MHz regime in biomimetic scaffolds and tissue specimens of blood clots, breast tumours, and bone. By capturing previously inaccessible viscoelastic behaviour across the wide frequency spectrum, our approach provides distinct and comprehensive mechanical signatures of tissues that may provide new mechanobiological insights and inform novel disease prognostication.

biophysics↗

bioRxiv2021

Light-sheet photonic force optical coherence elastography for high-throughput quantitative 3D micromechanical imaging

Microscale mechanical properties of the extracellular matrix (ECM) and dynamic cell-ECM interactions play an important role in physiological processes and disease. However, it remains a challenge for current mechanical characterization methods to combine quantitative 3D imaging of ECM mechanics with cellular-scale resolution and dynamic monitoring of cell-mediated changes to pericellular viscoelasticity. Here, we present light-sheet photonic force optical coherence elastography (LS-pfOCE) to address these challenges by leveraging a light-sheet for parallelized, non-invasive, and localized mechanical loading. We demonstrate the capabilities of LS-pfOCE by imaging the micromechanical heterogeneity of fibrous 3D collagen matrices and perform a live-cell study to image micromechanical heterogeneity induced by NIH-3T3 cells seeded in 3D fibrin constructs. We also show that LS-pfOCE is able to quantify temporal variations in pericellular viscoelasticity in response to altered cellular activity. By providing access to the spatiotemporal variations in the micromechanical properties of 3D complex biopolymer constructs and engineered cellular systems, LS-pfOCE has the potential to drive new discoveries in the rapidly growing field of mechanobiology.

biophysics↗