| “Design and Characterization of a Close-Proximity Thermoacoustic Sensor” by Jida Xing, Michael Choi, Woon Ang, Xiaojian Yu and Jie Chen was accepted by Ultrasound in Medicine & Biology (02/04/2013) 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 [ ... ] |
| “Application of Low-Intensity Pulsed Ultrasound to Increase Bio-ethanol Production” by Mohamed Shaheen, Michael Choi, Woon Ang, Yupeng Zhao, James Xing, Ray Yang, Jida Xing, Jian Zhang, and Jie Chen were accepted by the journal “Renewable Energy” (24/03/2013) 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 [ ... ] |
| “CXCR4 transfection of cord blood mesenchymal stromal cells using cationic liposome enhances their migration towards stromal cell-derived factor-1” by Leah A. Marquez-Curtis, Hilal Gul-Uludag, Peng Xu, Jie Chen and Anna Janowska-Wieczorek was accepted to (24/03/2013) 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. (07/02/2013)
|
| 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: (07/02/2013) 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 [ ... ] |
| Dr. Jie Chen is looking for NSERC Summer Undergraduate Students. Deadline Feb 1, 2013 (17/01/2013)
|
| “Applying Nano/micro-technologies for Gene Delivery in Plant Cells” by Jie Chen, Yollanda Hao, Xiaoyan Yang, Chuan He, Quanrong Gu, Min Huang, Yongzhong Shi and James Xing was invited to present at 8th International Symposium on Biocatalysis and Agricultu (04/12/2012) 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 [ ... ] |
| Low-intensity pulsed ultrasound-mediated stimulation of hematopoietic stem/progenitor cell viability, proliferation and differentiation in vitro Peng Xu, Hilal Gul-Uludag, Woon T. Ang, Xiaoyan Yang, Min Huang, Leah Marquez-Curtis, Locksley McGann, Anna J (31/10/2012)
|
| ULTRASOUND-ENHANCED MONOCLONAL ANTIBODY PRODUCTION James Xing, Xiaoyan Yang, Peng Xu, Woon T. Ang and Jie Chen was published by Ultrasound in Medicine & Biology 2012 (31/10/2012)
|
| “High-Throughput Quantitative Analysis with Cell Growth Kinetic Curves for Low-Copy Number Mutant Cells” by James Z Xing, Stephan Gabos, Biao Huang, Tianhong Pan and Jie Chen was published in Analytical & Bioanalytical Chemistry (31/10/2012)
|
| “A Low-Cost Intracellular Delivery System Based on Microbubble and High Gravity Field” by Chuan He, Quanrong Gu, Min Huang, Xiaoyan Yang, James Xing and Jie Chen in the 34th Annual International Conference of the IEEE Engineering in Medicine and Biology, (31/10/2012)
|
| Our article “Impact of Surfactants on Pb(Zr0.53Ti0.47)O3 Nanocrystal Formation” by Qian Wan, Quanrong Gu, James Xing and Jie Chen was accepted by Materials Letters on Oct. 10, 2012 (31/10/2012)
|
| “Microelectronic-sensing assay to detect presence of Verotoxins in human faecal samples” by J.Z. Xing, L. Zhu, B. Huang, J. Chen and S. Gabos was published in Journal of Applied Microbiology 113, 429–437, 2012. (31/10/2012)
|
| CALL FOR PAPERS IEEE Transactions on Biomedical Circuits and Systems Special Issue on ‘–Omics’ Based Companion Diagnostics for Personalized Medicine (31/10/2012) 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 [ ... ] |
| Yuzhi Hao, Xiaoyan Yang, Yongzhong Shi, James Xing, Janet Marowitch, Jianmin Chen, Jie Chen, “FITC Delivery into Plant Cells Using Magnetic Single-Wall Carbon Nanotubes”, (05/06/2012) 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.) |
| “Microstructure and Forming Process of Self-Assembly Pattern from Phospholipid Coated Gold Nanoparticles” by Yuzhi Hao, Ray Yang, and Jie Chen (20/04/2012) 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.
|
| “Recognition of Chemical Compounds in Contaminated Water using Time-dependent Multiple Dose Cellular Responses” by T.H. Pana, B. Huang, J.Z. Xing, W.P. Zhang, S. Gabos, and J. Chen, (12/03/2012)
to be published by Analytica Chimica Acta
|
| Efficient and rapid uptake of magnetic carbon nanotubes into human monocytic cells: implications for cell-based cancer gene therapy (09/01/2012) 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. |
| Conference article: Close-Proximity, Real-Time Thermoacoustic Sensors: Design, Characterization, and Testing (09/01/2012)
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 |
| Course announcement:EE 455 Engineering of Nanobiotechnological Systems (09/01/2012) *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
|
Other Articles
|