Label-Free Optical Mapping for Large-Area Biomechanical Dynamics of Multicellular Systems.

Mapping cellular activities over large areas is crucial for understanding the collective behaviors of multicellular systems. Biomechanical properties, such as cellular traction force, serve as critical regulators of physiological states and molecular configurations. However, existing technologies for mapping large-area biomechanical dynamics are limited by the small field of view and scanning nature.

Massive field-of-view sub-cellular traction force videography enabled by Single-Pixel Optical Tracers (SPOT).

We report a massive field-of-view and high-speed videography platform for measuring the sub-cellular traction forces of more than 10,000 biological cells over 13 mm at 83 frames per second. Our Single-Pixel Optical Tracers (SPOT) tool uses 2-dimensional diffraction gratings embedded into a soft substrate to convert cells' mechanical traction force into optical colors detectable by a video camera. The platform measures the sub-cellular traction forces of diverse cell types, including tightly connected tissue sheets and near isolated cells.

Massively Concurrent Sub-Cellular Traction Force Videography enabled by Single-Pixel Optical Tracers (SPOTs).

Unlabelled: We report a large field-of-view and high-speed videography platform for measuring the sub-cellular traction forces of more than 10,000 biological cells over 13mm at 83 frames per second. Our Single-Pixel Optical Tracers (SPOT) tool uses 2-dimensional diffraction gratings embedded into a soft substrate to convert cells' mechanical traction stress into optical colors detectable by a video camera. The platform measures the sub-cellular traction forces of diverse cell types, including tightly connected tissue sheets and near isolated cells.

Electrochemical biosensor with electrokinetics-assisted molecular trapping for enhancing C-reactive protein detection.

C-Reactive protein (CRP) is an essential biomarker relevant to various disease prognoses. Current biosensors require a significant amount of time for detecting CRP. To address this issue, this work proposes electrokinetic flow-assisted molecule trapping integrated with an impedance biosensor, where a driving signal in terms of a gated sine wave is provided to circularly arranged electrodes which detect proteins.

Distributed colorimetric interferometer for mapping the pressure distribution in a complex microfluidics network.

We demonstrate a novel platform for mapping the pressure distribution of complex microfluidics networks with high spatial resolution. Our approach utilizes colorimetric interferometers enabled by lossy optical resonant cavities embedded in a silicon substrate. Detection of local pressures in real-time within a fluid network occurs by monitoring a reflected color emanating from each optical cavity.

An implantable multifunctional neural microprobe for simultaneous multi-analyte sensing and chemical delivery.

A multifunctional chemical neural probe fabrication process exploiting PDMS thin-film transfer to incorporate a microfluidic channel onto a silicon-based microelectrode array (MEA) platform, and enzyme microstamping to provide multi-analyte detection is described. The Si/PDMS hybrid chemtrode, modified with a nano-based on-probe IrOx reference electrode, was validated in brain phantoms and in rat brain.

Deep, sub-wavelength acoustic patterning of complex and non-periodic shapes on soft membranes supported by air cavities.

Arbitrary patterning of micro-objects in liquid is crucial to many biomedical applications. Among conventional methodologies, acoustic approaches provide superior biocompatibility but are intrinsically limited to producing periodic patterns at low resolution due to the nature of standing waves and the coupling between fluid and structure vibrations. This work demonstrates a near-field acoustic platform capable of synthesizing high resolution, complex and non-periodic energy potential wells.

Intracellular Photothermal Delivery for Suspension Cells Using Sharp Nanoscale Tips in Microwells.

Efficient intracellular delivery of biomolecules into cells that grow in suspension is of great interest for biomedical research, such as for applications in cancer immunotherapy. Although tremendous effort has been expended, it remains challenging for existing transfer platforms to deliver materials efficiently into suspension cells. Here, we demonstrate a high-efficiency photothermal delivery approach for suspension cells using sharp nanoscale metal-coated tips positioned at the edge of microwells, which provide controllable membrane disruption for each cell in an array.

Plasma Homocysteine and Glutathione Are Independently Associated With Estimated Glomerular Filtration Rates in Patients With Renal Transplants.

Background: Elevated levels of plasma homocysteine could, through homocysteine oxidation, induce the overproduction of reactive oxygen species, leading to a reduction in glutathione-related antioxidants, and may impair graft functions in patients with renal transplants. The purpose of this study was to determine whether plasma homocysteine, glutathione, or its related antioxidants were related to graft functions in patients with renal transplants.

Patients And Methods: We recruited 66 patients (mean age 48.

Flexible, multifunctional neural probe with liquid metal enabled, ultra-large tunable stiffness for deep-brain chemical sensing and agent delivery.

Flexible neural probes have been pursued previously to minimize the mechanical mismatch between soft neural tissues and implants and thereby improve long-term performance. However, difficulties with insertion of such probes deep into the brain severely restricts their utility. We describe a solution to this problem using gallium (Ga) in probe construction, taking advantage of the solid-to-liquid phase change of the metal at body temperature and probe shape deformation to provide temperature-dependent control of stiffness over 5 orders of magnitude.

Lift-off cell lithography for cell patterning with clean background.

We developed a highly efficient method for patterning cells by a novel and simple technique called lift-off cell lithography (LCL). Our approach borrows the key concept of lift-off lithography from microfabrication and utilizes a fully biocompatible process to achieve high-throughput, high-efficiency cell patterning with nearly zero background defects across a large surface area. Using LCL, we reproducibly achieved >70% patterning efficiency for both adherent and non-adherent cells with <1% defects in undesired areas.

Liquid Metal-Based Multifunctional Micropipette for 4D Single Cell Manipulation.

A novel manufacturing approach to fabricate liquid metal-based, multifunctional microcapillary pipettes able to provide electrodes with high electrical conductivity for high-frequency electrical stimulation and measurement is proposed. 4D single cell manipulation is realized by applying multifrequency, multiamplitude, and multiphase electrical signals to the microelectrodes near the pipette tip to create 3D dielectrophoretic trap and 1D electrorotation, simultaneously. Functions such as single cell trapping, patterning, transfer, and rotation are accomplished.

A Novel Thermal Bubble Valve Integrated Nanofluidic Preconcentrator for Highly Sensitive Biomarker Detection.

In this study, we developed a new immunosensor that can achieve an ultralow detection limit and high sensitivity. This new device has an electrokinetic trapping (EKT)-based nanofluidic preconcentrator, which was integrated with oscillating bubble valves, to trap concentrated antigen and immunobeads. During the immunoassay process, oscillating bubbles rapidly grew and acted as control valves and to block the microchannel.

[Improve the Rate of Bone Collection at Human Tissue Banks].

Background: Lack of familiarity with collection and inspection procedures, incorrect bone-packaging procedures, and unclear instructions for bone placement during storage are primary reasons for the resultant low bone collection pass rate of bone banks. Moreover, 8 cases / operations were directly affected by this problem, which caused bone-nail dislocations during the post-operative period that nearly caused medical disputes.

Purpose: The present project was designed to improve the pass rate of the bone of the human organ to 95%.

Real-time dual-loop electric current measurement for label-free nanofluidic preconcentration chip.

An electrokinetic trapping (EKT)-based nanofluidic preconcentration device with the capability of label-free monitoring trapped biomolecules through real-time dual-loop electric current measurement was demonstrated. Universal current-voltage (I-V) curves of EKT-based preconcentration devices, consisting of two microchannels connected by ion-selective channels, are presented for functional validation and optimal operation; universal onset current curves indicating the appearance of the EKT mechanism serve as a confirmation of the concentrating action. The EKT mechanism and the dissimilarity in the current curves related to the volume flow rate (Q), diffusion coefficient (D), and diffusion layer (DL) thickness were explained by a control volume model with a five-stage preconcentration process.

Molecular characterization of mungbean (Vigna radiata L.) starch branching enzyme I.

Mungbean (Vigna radiata L. cv. Tainan no.

Cloning, characterization, and expression of mungbean ( Vigna radiata L.) starch branching enzyme II cDNA in Escherichia coli.

Full-length starch branching enzyme II (SBE, EC 2.4.1.