Showing papers by "Tingrui Pan published in 2015"

Flexible Transparent Iontronic Film for Interfacial Capacitive Pressure Sensing

Abstract: A flexible, transparent iontronic film is introduced as a thin-film capacitive sensing material for emerging wearable and health-monitoring applications. Utilizing the capacitive interface at the ionic-electronic contact, the iontronic film sensor offers a large unit-area capacitance (of 5.4 μF cm(-2) ) and an ultrahigh sensitivity (of 3.1 nF kPa(-1) ), which is a thousand times greater than that of traditional solid-state counterparts.

A large scale screen reveals genes that mediate electrotaxis in Dictyostelium discoideum

Abstract: Directional cell migration in an electric field, a phenomenon called galvanotaxis or electrotaxis, occurs in many types of cells, and may play an important role in wound healing and development. Small extracellular electric fields can guide the migration of amoeboid cells, and we established a large-scale screening approach to search for mutants with electrotaxis phenotypes from a collection of 563 Dictyostelium discoideum strains with morphological defects. We identified 28 strains that were defective in electrotaxis and 10 strains with a slightly higher directional response. Using plasmid rescue followed by gene disruption, we identified some of the mutated genes, including some previously implicated in chemotaxis. Among these, we studied PiaA, which encodes a critical component of TORC2, a kinase protein complex that transduces changes in motility by activating the kinase PKB (also known as Akt). Furthermore, we found that electrotaxis was decreased in mutants lacking gefA, rasC, rip3, lst8 ,o rpkbR1, genes that encode other components of the TORC2-PKB pathway. Thus, we have developed a high-throughput screening technique that will be a useful tool to elucidate the molecular mechanisms of electrotaxis.

Microfluidic-Enabled Print-to-Screen Platform for High-Throughput Screening of Combinatorial Chemotherapy

Abstract: Since the 1960s, combination chemotherapy has been widely utilized as a standard method to treat cancer. However, because of the potentially enormous number of drug candidates and combinations, conventional identification methods of the effective drug combinations are usually associated with significantly high operational costs, low throughput screening, laborious and time-consuming procedures, and ethical concerns. In this paper, we present a low-cost, high-efficiency microfluidic print-to-screen (P2S) platform, which integrates combinatorial screening with biomolecular printing for high-throughput screening of anticancer drug combinations. This P2S platform provides several distinct advantages and features, including automatic combinatorial printing, high-throughput parallel drug screening, modular disposable cartridge, and biocompatibility, which can potentially speed up the entire discovery cycle of potent drug combinations. Microfluidic impact printing utilizing plug-and-play microfluidic cartridges is experimentally characterized with controllable droplet volume and accurate positioning. Furthermore, the combinatorial print-to-screen assay is demonstrated in a proof-of-concept biological experiment which can identify the positive hits among the entire drug combination library in a parallel and rapid manner. Overall, this microfluidic print-to-screen platform offers a simple, low-cost, high-efficiency solution for high-throughput large-scale combinatorial screening and can be applicable for various emerging applications in drug cocktail discovery.

Telemedical wearable sensing system for management of chronic venous disorders

Abstract: A telemedical interface pressure monitoring system is provided for intermittent or continuous monitoring of the pressure that occurs at the interface between the body and a support surface such as with a compression device, cast or resting surface. The system simultaneously measures interface pressure at multiple compression positions as well as provide real-time measurement data to both patients and clinicians. The system uses an array of one or more sensors and a data collection and transmission node with a microprocessor and transmitter/receiver that transmits the sensor data to a receiver such as a mobile device or cloud or clinic server for remote display, evaluation and automatic recording. Remote receivers can also control compression devices associated with the node.

Reconfigurable microfluidic dilution for high-throughput quantitative assays

Abstract: This paper reports a reconfigurable microfluidic dilution device for high-throughput quantitative assays, which can easily produce discrete logarithmic/binary concentration profiles ranging from 1 to 100-fold dilution in parallel from a fixed sample volume (e.g., 10 μL) without any assistance of continuous fluidic pump or robotic automation. The integrated dilution generation chip consists of switchable distribution and collection channels, metering reservoirs, reaction chambers, and pressure-activatable Laplace valves. Following the sequential loading of a sample, a diluent, and a detection reagent into their individual metering chambers, the top microfluidic layer can be reconfigured to collect the metered chemicals into the reaction chambers in parallel, where detection will be conducted. To facilitate mixing and reaction in the microchambers, two acoustic microstreaming actuation mechanisms have been investigated for easy integrability and accessibility. Furthermore, the microfluidic dilution generator has been characterized by both colorimetric and fluorescent means. A further demonstration of the generic usage of the quantitative dilution chip has utilized the commonly available bicinchoninic acid (BCA) assay to analyse the protein concentrations of human tissue extracts. In brief, the microfluidic dilution generator offers a high-throughput high-efficiency quantitative analytical alternative to conventional quantitative assay platforms, by simple manipulation of a minute amount of chemicals in a compact microfluidic device with minimal equipment requirement, which can serve as a facile tool for biochemical and biological analyses in regular laboratories, point-of-care settings and low-resource environments.

Design, Fabrication, and In Vitro Testing of an Anti-biofouling Glaucoma Micro-shunt.

Abstract: Glaucoma, one of the leading causes of irreversible blindness, is a progressive neurodegenerative disease. Chronic elevated intraocular pressure (IOP), a prime risk factor for glaucoma, can be treated by aqueous shunts, implantable devices, which reduce IOP in glaucoma patients by providing alternative aqueous outflow pathways. Although initially effective at delaying glaucoma progression, contemporary aqueous shunts often lead to numerous complications and only 50% of implanted devices remain functional after 5 years. In this work, we introduce a novel micro-device which provides an innovative platform for IOP reduction in glaucoma patients. The device design features an array of parallel micro-channels to provide precision aqueous outflow resistance control. Additionally, the device’s microfluidic channels are composed of a unique combination of polyethylene glycol materials in order to provide enhanced biocompatibility and resistance to problematic channel clogging from biofouling of aqueous proteins. The microfabrication process employed to produce the devices results in additional advantages such as enhanced device uniformity and increased manufacturing throughput. Surface characterization experimental results show the device’s surfaces exhibit significantly less non-specific protein adsorption compared to traditional implant materials. Results of in vitro flow experiments verify the device’s ability to provide aqueous resistance control, continuous long-term stability through 10-day protein flow testing, and safety from risk of infection due to bacterial ingression.

Integrated fluidic flow network for fluid management

Abstract: An apparatus (100) and method is presented for the management of fluid flow utilizing different adjacent wettability regions (102, 104) to form a fluidic network structure on a substrate (106). The fluidic network structure may include liquid-absorptive fluidic channels (118), where the fluid can flow within these channels (118) and be removed from the substrate (106). Fluid can be moved by gravitational force, compression force, capillary force and surface tension force.

Reconfigurable microfluidic dilution generation for quantitative assay

Abstract: In this paper, we present a reconfigurable microfluidic dilution device for high-throughput quantitative assays, without the assistance of continuous fluidic pump or vacuum source. This device is capable to produce discrete logarithmic concentration profiles ranging from 1 to 100 fold dilution in parallel from a fixed sample volume (e.g., 10 µL). To facilitate mixing and reactions in the chambers, two acoustic microstreaming actuation mechanisms have been investigated for easy integratability and accessibility. We characterized the dilution performance by both colorimetric and fluorescent means.

High-throughput print-to-screen (P2S) platform for combinatorial chemotherapy

Abstract: This paper reports a microfluidic enabled print-to-screen (P2S) platform, which can achieve low-cost, high-throughput, high-precision printing with plug-and-play disposable cartridge, as well as parallel screening with minimized crosstalk The performance of the P2S platform is characterized and, using this platform, the cell-killing performance of 3-out-of-10 drug combinations towards ovarian cancer cell is, for the first time, studied and as a result, 15 out of 175 drug combinations are newly identified to exert potent cancer cell toxicity This demonstrates the potent applicability of P2S platform for combinatorial chemotherapy, which can greatly speed up the entire cycle of drug cocktail discovery