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Wijesekara, P.

Publications and source records attributed to Wijesekara, P..

2 recordsLinked to original sources

Engineering Rotating Apical-Out Airway Organoid for Assessing Respiratory Cilia Motility

Motile cilia project from the airway apical surface and directly interface with inhaled external environment. Due to cilias nanoscale dimension and high beating frequency, quantitative assessment of their motility remains a sophisticated task. Here we described a robust approach for reproducible engineering of apical-out airway organoid (AOAO) of defined size. Propelled by exterior-facing cilia beating, the mature AOAO exhibited stable rotational motion when surrounded by Matrigel. We developed a computational framework leveraging computer vision algorithms to quantify AOAO rotation and validated its correlation with direct measurement of cilia motility. We further established the feasibility of using AOAO rotation to recapitulate and measure defective cilia motility caused by chemotherapy-induced toxicity and by CCDC39 mutations in cells from primary ciliary dyskinesia patient. We expect our rotating AOAO model and the associated computational pipeline to offer a generalizable framework to expediate modeling of and therapeutic development for genetic and environmental ciliopathies.

bioengineering↗

Super-resolution vibrational imaging using expansion stimulated Raman scattering microscopy

Stimulated Raman scattering (SRS) microscopy is an emerging technology that provides high chemical specificity for endogenous biomolecules and can circumvent common constraints of fluorescence microscopy including limited capabilities to probe small biomolecules and difficulty resolving many colors simultaneously due to spectral overlap. However, the resolution of SRS microscopy remains governed by the diffraction limit. To overcome this, we describe a new technique called Molecule Anchorable Gel-enabled Nanoscale Imaging of Fluorescence and stImulatEd Raman Scattering microscopy (MAGNIFIERS), that integrates SRS microscopy with expansion microscopy (ExM). ExM is a powerful strategy providing significant improvement in imaging resolution by physical magnification of hydrogel-embedded preserved biological specimens. MAGNIFIERS offers chemical-specific nanoscale imaging with sub-50 nm resolution and has scalable multiplexity when combined with multiplex Raman probes and fluorescent labels. We used MAGNIFIERS to visualize nanoscale features in a label-free manner with C-H vibration of proteins, lipids and DNA in a broad range of biological specimens, from mouse brain, liver and kidney to human lung organoid. In addition, we applied MAGNIFIERS to track nanoscale features of protein synthesis in protein aggregates using metabolic labeling of small metabolites. Finally, we used MAGNIFIERS to demonstrate 8-color nanoscale imaging in an expanded mouse brain section. Overall, MAGNIFIERS is a valuable platform for super-resolution label-free chemical imaging, high-resolution metabolic imaging, and highly multiplexed nanoscale imaging, thus bringing SRS to nanoscopy.

bioengineering↗