Abstract: Although the radiation force balance is the gold standard for measuring ultrasound intensity, it is not possible for real-time monitoring in certain settings, for example bioreactors, or in clinic to measure ultrasound intensities during treatment. Foreseeing these needs, we have proposed a close-proximity thermoacoustic sensor. In this article, the design, characterization, testing, and implementation of such a sensor is presented. A plexiglass sensor with a 20 mm diameter, and a 2 mm long absorber was designed and tested against low intensity pulsed ultrasound generated at  a 1.5 MHz frequency, 20% duty cycle, 1 kHz pulse repetition frequency, and intensities between 30 and 120 mW/cm2. The sensor captures the beam, converts the ultrasound power into heat, and indirectly measures the spatial average time average ultrasound intensity (Isata) by dividing the calculated power by the beam-cross-section (or the nominal area of the transducers). A thin copper sheet was adhered to the back face of the sensor to increase heat diffusivity 1000-fold, enabling a uniform temperature distribution across the back face. An embedded system design was implemented using an Atmel microcontroller programmed with a least squares algorithm to fit measured temperature vs. time data to a model describing the temperature rise averaged across the backside of the sensor in relation to the applied ultrasound intensity. After calibrating the sensor to the transducer being measured, the t [ ... ]

Abstract: We explored the application of Low-Intensity Pulsed Ultrasound (LIPUS) technology to improve the metabolic activity of microorganisms. In this study we showed that LIPUS improves bioethanol production from lingocellulosic biomass. We determined specific LIPUS conditions to increase the metabolic activity of both the cellulose degrading fungus, Trichoderma reesei Rut C-30 and the ethanol producing yeast, Saccharomyces cerevisiae. LIPUS conditions of 1.5 MHz, 20% duty cycle, 80 mW/cm2 intensity, 5 minutes exposure and 12 exposures per day were found to improve the activity of the organisms the most. These LIPUS treatment conditions increased cellulase production by T. reesei by 16±6%. The same LIPUS treatment conditions induced a 31±10% increase in ethanol production by S. cerevisiae which implies a cumulative improvement of 52±16% in lignocellulosic bioethanol production with LIPUS. This observation shows a new potential for LIPUS in the improvement of lignocellulosic bioethanol production to make it a sustainable energy source. Figure 6: (A) SEM picture of a T. reesei sample that received LIPUS treatment during fermentation shows shrinking mycelia with crack openings on the mycelial wall. These cracks and openings in the mycelia caused the release of the intracellular contents of cellulase enzymes, which correlates with high cellulase activity. (B) SEM picture of a T. reesei sample that received no LIPUS treatment during fermentation shows more intact mycelia  [ ... ]

Background: The interaction between stromal cell-derived factor (SDF)-1 and its receptor CXCR4 is one of the mechanisms by which mesenchymal stromal cells (MSC) are recruited to sites of injury. SDF-1 is upregulated in damaged tissues, but because the surface expression of CXCR4 on cultured MSC is low, we investigated whether the delivery of CXCR4 into MSC using the cationic lipsomal reagent IBAfect would increase their migration towards SDF-1. Methods: We examined i) the effect of MSC confluency, passage number, duration of transfection, and amount of IBAfect and plasmid on transfection efficiency as determined by flow cytometric analysis of CXCR4; and ii) whether IBAfect-mediated CXCR4 transfection affected the viability, proliferation and differentiation of MSC, as well as their response towards an SDF-1 gradient in a trans-Matrigel migration assay. Results: We found that transfection efficiency of up to 40% was achieved after 24-h transfection of 50% confluent MSC (at passage 4) with an IBAfect:plasmid ratio of 3.6 μL:0.6 μg, and CXCR4 transcript expression in transfected MSC was 105-fold higher than in non-transfected cells. Transfected MSC retained their ability to differentiate to osteocytes and chondrocytes but had lower proliferation. Importantly, overexpression of surface CXCR4 using IBAfect significantly increased (over 3-fold) the number of cells migrating towards an SDF-1 gradient relative to cells migrating to media alone, compared to non-transfected cells ( [ ... ]

February 1, 2013. Dr. Jie Chen received the Member of the Year (2012) Award by the Association of Chinese Canadian Professors in recognition of his outstand academic achievements and society service.

A gifted Chinese student, Mr. Tianlin Yang, mentioned that he was impressed by our research lab and helped him to make decisions to come to U of A.  Please refer to the following two reports: Investing in international leaders http://www.news.ualberta.ca/article.aspx?id=2EBFA08B3092404B89AF5958C12EE7E3 By Michael Davies-VennSeptember 25, 2012 University of Alberta chancellor Ralph Young hosted a reception for international scholarship recipients Sept. 24. (Photo: John Ulan) (Edmonton) As researchers and students continue working to address some of the world’s most pressing needs, it’s important, says Murray Gray, U of A vice-provost (academic), that viewpoints from around the world are part of that effort. In keeping with its commitment as a global citizen, the university is investing in students from around the world by providing scholarships that enable hundreds of them to study at the U of A. It’s a twin approach that also sees the university sending Canadian students around the world through its Education Abroad program. The sense that much of the world is now represented on campus resonated with Gray as he welcomed international undergraduate, sponsored and education abroad students Sept. 24 at the Chancellor’s Reception for International Scholarship Recipients. Looking at a group of students from just about every continent, he said he sees how the U of A has become significantly internationalized. A community that enriches a university “This y [ ... ]

Summer Undergraduate Student Research Awards are again being offered by the Natural Sciences and Engineering
Research Council of Canada (NSERC).  Deadline Feb 1, 2013. The objectives of the program are to stimulate the interest of undergraduate students in research and to encourage them to continue into graduate studies.  The NSERC contribution for successful applications is $1125 per month for a period of 4 months.  The supervisor must supplements this by at least $281.25 per month. The award receipients are selected based on (i) their GPA of  the last two academic terms (for traditional students it will be
Winter'11 and Fall'11), (ii) course units, (iii) research proposal, and (iv) year of study.  The ECE Department has been allocated 16 awards this year.  All applications are to be completed electronically using NSERC’s online application system  http://www.nserc-crsng.gc.ca/OnlineServices-ServicesEnLigne/Index_eng.asp. As per NSERC’s guidelines, paper applications will not be accepted! The online application is completed in two parts.  
 1. Once the students have completed Part 1 of the application. This includes upload of official transcripts. Students will then forward 
     their application reference number onto their supervisor who will need to complete Part 2 of the student’s application. 
 2. Supervisors are responsible for ensuri [ ... ]

Abstract Nano/microtechnologies have been widely used in delivering genetic materials into mammalian cells. However, due to cell wall, not much success has been reported on delivering genetic materials into plant cells. In this presentation, we will report our recent success of using two novel methods that can be used to deliver target genes into plant cells.  Fluorescein isothiocyanate (FITC), fluorescein isothiocyanate (FITC)-Dextran (40kDa) and plasmid of green fluorescent protein (GFP) were used as model systems. The first approach uses “magnetic nanodart” (M-nanodart) design, in which magnetic nanoparticles covalently bind to biomolecules. With the assist of external magnetic field, M-nanodarts were dragged into canola and carrot cells. Most biomolecules entered cell cytoplasm while few entered cell nucleus confirmed by Transmission Electron Microscopy (TEM). No significant cytotoxicity was found with cell viability approximately 100%. The delivery rate of FITC for this method is 100% based on flow cytometer (FACS) results. The second method is microbubble-based approach. The sizes of these microbubbles are around 1 to 2 μm.  The burst of microbubbles can transiently enlarge the pores or cause cavities on cell membrane under the high-speed centrifugation. The biomolecules can enter canola cells easier than those without microbubbles. Although the cell survivability, depending on centrifugation speed, is not as high as M-nanodart approach, microbubbles are [ ... ]

Abstract: Low-intensity pulsed ultrasound (LIPUS) was shown to enhance the growth of human mesenchymal stem cells. In this work, we evaluated the effect of LIPUS stimulation on the viability, proliferation and differentiation of hematopoietic stem/progenitor cells (HSPC) from fresh and cryopreserved peripheral blood leukapheresis product (LP), as well as cord blood (CB). LP and CB CD34+ HSPC were stimulated by LIPUS for 10 minutes each day for 4 days. Cell viability, proliferation and differentiation were assessed on day 5 by viable cell counting, MTS proliferation assay, flow cytometry, and colony-forming unit assay. We found that LIPUS stimulation: (i) enhanced the proliferation of fresh HSPC and maintained the viability of cryopreserved HSPC in vitro; ii) did not affect the percentage of CD34+ and CD14+ cells; and (iii) enhanced burst-forming unit-erythroid colony formation. Hence, we suggest that this novel LIPUS stimulation approach might enhance the efficacy of clinical transplantation and cellular therapies using HSPC. Fig: The experimental set-up of LIPUS mediated HSPC stimulation.

Abstract: With the rapidly growing demand for monoclonal antibody (mAb)–based products, new technologies are urgently needed to increase mAb production while reducing manufacturing costs. To solve this problem, we report our research findings of using low-intensity pulsed ultrasound (LIPUS) to enhance mAb production. LIPUS with frequency of 1.5 MHz and pulse repetition frequency of 1 kHz, as well as duty cycle of 20%, was used to stimulate hybridoma cells to enhance the production of mAb, anti-CD4 (hybridoma GK1.5). The enzyme-linked immunosorbent assay results show a 60.42 ± 7.63% increase of mAb expression in hybridoma cells. The evidence of structural changes of the cellular outer membrane in both transmission electron microscopy and scanning electron microscopy images and the more than 20% lactate dehydrogenase release indicates that the increased mAb production is related to the increased cell permeability induced by LIPUS. This value-added ultrasound technology provides a potential cost-effective solution for pharmaceutical companies to manufacture mAb-based drugs. The technology, in turn, can reduce the drug manufacturing costs and decrease health care spending. Fig: SEM images for hybridoma cells. (a) Control cells without ultrasound treatment; (b) the surface of the control cells looks smooth without herpetiform structure changes; (c) hybridoma cells treated with 537.53 mPa; (d) several herpetiform structural changes (arrows) appeared on the outer membran [ ... ]

Abstract: The mutation rate in cells induced by environmental genotoxic hazards is very low and difficult to be detected using traditional cell counting assays. The established genetic toxicity tests currently recognized by regulatory authorities, such as conventional Ames and hypoxanthine guanine phosphoribosyl-transferase (HPRT) assays, are not well suited for higher throughput screening as they require large amounts of test compounds and are very time consuming. In this study, we developed a novel cell-based assay for quantitative analysis of low-number cell copies with HPRT mutation induced by an environmental mutagen. The HPRT gene mutant cells induced by the mutagen were selected by 6-thioguanine (6-TG) and the cell’s kinetic growth curve monitored by a real-time cell electronic sensor (RT-CES) system. When a threshold is set up at a certain Cell Index (CI) level, samples with different initial mutant cell copies take different amounts of time in order for their growth (or CI accumulation) to cross this threshold. The more cells that are initially seeded in the test well, the faster the cell accumulation and therefore the shorter the time required crossing this threshold. Therefore, the culture time period required to cross the threshold of each sample corresponds to the original number of cells in the sample. A Mutant cell growth time Threshold (MT) value of each sample can be calculated to predict the number of original mutant cells. For mutagenesis determinat [ ... ]

Paper Abstract: In this paper, we developed a low-cost intracellular delivery system based on microbubble and high gravity field. We successfully delivered FITC-Dextran (40kD) into hard-to-deliver THP-1 cells. The results showed that our method achieved high delivery efficiency up to 80%. It was found that the delivery efficiency and cell viability were closely related to the centrifuge speed. We speculated that the burst of microbubbles causes transient pore opening thus increasing the chance of biomolecules entering cells. This fast, low-cost and easy-to-operate protocol is very promising for delivering therapeutic genes and drugs into any cells which do not actively take up extracellular materials. This method is most effective for in-vitro delivery, but after delivery, treated cells might be injected back to human for in-vivo imaging. Figure Caption: An innovative intracellular delivery method was developed by centrifuging the cells with microbubbles at high speed. It was proved that under high speed centrifugation, the centrifugal force leads to cell deformation. By controlling the centrifugation speed, the cell membrane structure is deformed to different degrees. As a result, the bursting of microbubbles, which happens during the centrifugation process, creates pores on the cell membrane which then leads to the intracellular diffusion of biomaterials. The maximum delivery efficiency achieved was around 80%.

Paper Highlights: In this paper, we propose a surfactant-assisted synthesis method to control the morphology of single-crystalline Pb(Zr0.53Ti0.47)O3(PZT), either in nanohexagon or in nanorod shapes. Experiments were designed to understand the growth mechanism of the nanostructure formation. To our best knowledge, no method for preparation of single crystalline PZT nanohexagons/nanorods has been reported in the literature.
High-resolution TEM image of an individual PZT nanohexagon and its corresponding selected area electron diffraction (SAED) pattern.



High-resolution TEM image of a typical PZT nanorod. b) High-resolution TEM image of an individual PZT nanorod and its corresponding Nano Beam diffraction (NBD) pattern.

Paper abstract: We have performed in-house assessments of the real-time cell electronic sensing (RT-CES) assay to measure Verotoxin induced by Escherichia coli (VTEC) in a conventional laboratory setting. The results obtained by the RT-CES assay agree with the data generated by the crystal violet assay. The RT-CES assays are simple to operate and provide sensitive measurements comparable to the crystal violet assay. The RT-CES assay also significantly shortens the testing time from 48 to 72 h required by the crystal Violet Assay to only 15 h. The assay has been successfully used in screening for Verocytotoxigenic E.coli in human faecal samples. A schematic illustration of the mechanism of real-time cell electronic sensing Verotoxin assay. The presence of cells affects the local ionic environment at the electrode ⁄ solution interface, leading to an increase in the electrode impedance. If more cells attached to the electrodes, a greater electrode impedance is observed, resulting in a larger cell index. On the other hand, cell index decreases when cells dies from exposure to Verotoxins. If the toxins were neutralized by antibodies, the test cells continually grow and thus cell index increases.

Companion diagnostics are essential to the success of personalized medicine. For example, the electronic glucose sensor is a success story of companion diagnostics, and millions of diabetic patients around the world today are benefiting from the device in monitoring their health and making informed decisions about medications and treatment strategies. If used properly, companion diagnostic tools can help to change our dietary habits, lifestyle, or exercise routines for disease prevention. With the rapid advances made in high throughput molecular biology, such as genomics, proteomics, and metabolomics, in the past two decades, scientists, researchers and engineers are beginning to harvest the power of ‘–omics’ to develop companion diagnostic circuits and systems that can be used to diagnose, monitor or predict not just one disease, but multiple diseases simultaneously, as well as allow the management of disease at the personal level, i.e., accordingly to the biology of individual patients. Foreseeing this emerging trend, the purpose of this special issue is: (i) to provide a road map of ‘–omics’ networks, circuits and systems; (ii) to encourage cross-disciplinary collaboration in this emerging research field; and (iii) to report the cutting edge development of these circuits and devices with translational potential into the clinics. Manuscripts describing original research as well as reviews of emerging directions are solicited for this special issue, covering a r [ ... ]

was accepted by Journal of Nanoscience and Nanotechnology on April 24, 2012. Abstract:   In this paper, fluorescein isothiocyanate (FITC) was covalently bonded with magnetic single-walled carbon nanotubes (mSWCNTs) that were purified using our previous method. To demonstrate our design, mSWCNT-FITC was delivered into plant cells (canola and carrot cells) driven by external magnetic forces.  From FACS results, the FITC delivery efficiency was about 100% for both two canola and carrot protoplasts, which were further confirmed by the confocal and sectional TEM images.  Some mSWCNTs were found trapped both inside the endosomes of canola protoplast and outside endosome near the nuclear membrane of carrot protoplast according to the sectional TEM images. All results showed that mSWCNT is a good delivery carrier for biomolecules.                     Figure: Confocal images of canola and carrot protoplasts/mSWCNT-FITC. (Because the size of carrot cell is much smaller than that of canola cell, the green fluorescent signal in carrot cell is weaker than the canola cell.)

Was accepted by Advanced Science, Engineering and Medicine Vol. 4, pp. 1–5, 2012 (refer to the attached published article) Abstract: This article reports the microstructure and forming process of self-assembly pattern from phospholipid coated gold nanoparticles. Gold nanoparticles coated with phospholipids can self-assemble to form fractal dendritic patterns whose morphology depends on the ratio of gold to phospholipids, the gold nanoparticles concentration, substrate material and drying temperature, and whose microstructure is discontinuous gold nanoparticles covered with crystal sodium chloride according to the analysis of atomic force microscope (AFM) and scanning electron microscopy (SEM) and elemental analysis by Auger spectroscopy. The formation process of the self-assembly pattern was monitored by an off-line (different position at the same droplet) monitoring method.
                                                                               Fig: Optical microscope images of self-assembly patterns with different concentrations of phospholipid coated GNPs.   Full paper

 to be published by Analytica Chimica Acta


Abstract An early determination of toxicant compounds of water contaminations can gain critical time to protect citizens’ health and save substantial amounts of medical costs. To determine toxins in real time, a multi-dose classification algorithm using cellular state variable identification (CSVID) is developed in this paper. First, the dynamic cytotoxicity response profiles of living cells are measured using a real-time cell electronic sensing (RT-CES) system. Changes in cell number expressed as cell index (CI) are recorded on-line as time series. Then CSVID, which reflects the cell killing, cell lysis and certain cellular pathological changes, is extracted from those dynamic cellular responses. Finally, a support vector machine (SVM) algorithm based on CSVID is employed to classify chemical compounds and determine their analogous cellular response pathway. In order to increase the classification accuracy, a majority vote of the class labels is also proposed. Several validation studies demonstrate that CSVID-based classification algorithm has great potential in distinguishing the cytotoxicity response of the cells in the presence of toxins.

Hilal Gul-Uludag, Weibing Lu, Peng Xu, James Xing, and Jie Chen Paper highlights: (published Biotechnol Lett. 2012 Jan 28) Monocyte-based gene therapies in cancer have been hampered by either the resistance of these cells to non-viral molecular delivery methods or their poor trafficking to the tumor site after their ex-vivo manipulations. It has been recently shown that magnetic nanoparticles (MNP)-loaded, genetically engineered monocytes were efficiently delivered to tumor site by external magnetic field. However, MNP have not been ideal magnetic delivery tools due to their spherical shape. Hence in this work, we investigated the cellular uptake efficiency and cytotoxicity of fluorescein isothiocyanate (FITC) labelled magnetic carbon nanotubes (FITC-mCNT) in human monocytic leukemia cell line THP-1 for their future application in cell-based gene therapy against cancer. We found that the uptake of FITC-mCNT into THP-1 cells reached 100% only 1 hr after the delivery. Confocal imaging confirmed that FITC-mCNT entered the cell cytoplasm and even into the nucleus. We have also demonstrated that FITC-mCNT uptake did not compromise cell viability. In summary, we suggest that this novel mCNT-based delivery system might enhance cell-based cancer gene therapies. 

Close-Proximity, Real-Time Thermoacoustic Sensors: Design, Characterization, and Testing Michael Choi, Woon Ang, and Jie Chen accepted by IEEE International Symposium on Circuits and Systems 2012, May, South Korea
Paper highlights: The application of ultrasound can promote cell growth. However, under-treatment of ultrasound can lead to an incomplete treatment that may not produce the desired results, while over-treatment of ultrasound can lead to cell death. Thermal sensors that measure the transformation of the incident ultrasonic energy into heat, otherwise known as thermoacoustic sensors, have the potential to be a simple, inexpensive method for determining the acoustic intensity outputted by an ultrasound transducer. The advantage of a thermoacoustic sensor is its simplicity: it does not require any complicated setup procedures, or calculations. Previous thermoacoustic sensor operation has required the sensor and transducer to be placed in a water tank, similar to hydrophone or radiation force balance measurements. To further simplify the thermoacoustic sensor operation, we have designed and tested a close-proximity thermoacoustic sensor that can determine radiated ultrasound intensities when placed in contact with a transducer. Furthermore, our device performs all the required computations in real time using an embedded system design, allowing the user to quickly and conveniently measure ultrasound intensities.

*3.0 (fi 6) (3-0-0) Microfluidic and nanobiotechnological devices. Fabrication techniques for devices: self-assembly, lithographic technologies. Applications of nanobiotechnology in computing, electronics, human health, environment and manufacture. For details, please refer to the course syllabus. Syllabus for EE455