Browsing by Author "Li, Bor-Ran"

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A Novel Metallo-beta-Lactamase Involved in the Ampicillin Resistance of Streptococcus pneumoniae ATCC 49136 Strain
(2016-05-23)
Chang, Chia-Yu
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Lin, Hui-Jen
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Li, Bor-Ran
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Li, Yaw-Kuen
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分子醫學與生物工程研究所
Streptococcus pneumoniae, a penicillin-sensitive bacterium, is recognized as a major cause of pneumonia and is treated clinically with penicillin-based antibiotics. The rapid increase in resistance to penicillin and other antibiotics affects 450 million people globally and results in 4 million deaths every year. To unveil the mechanism of resistance of S. pneumoniae is thus an important issue to treat streptococcal disease that might consequently save millions of lives around the world. In this work, we isolated a streptococci-conserved L-ascorbate 6-phosphate lactonase, from S. pneumoniae ATCC 49136. This protein reveals a metallo-beta-lactamase activity in vitro, which is able to deactivate an ampicillin-based antibiotic by hydrolyzing the amide bond of the beta-lactam ring. The Michaelis parameter (K-m) = 25 mu M and turnover number (k(cat)) = 2 s(-1) were obtained when nitrocefin was utilized as an optically measurable substrate. Through confocal images and western blot analyses with a specific antibody, the indigenous protein was recognized in S. pneumoniae ATCC 49136. The protein-overexpressed S. pneumonia exhibits a high ampicillin-tolerance ability in vivo. In contrast, the protein-knockout S. pneumonia reveals the ampicillin-sensitive feature relative to the wild type strain. Based on these results, we propose that this protein is a membrane-associated metallo-beta-lactamase (MBL) involved in the antibiotic-resistant property of S. pneumoniae.
An antifouling peptide-based biosensor for determination of Streptococcus pneumonia markers in human serum
(2020-03-01)
Chang, Po-Han
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Weng, Chang-Ching
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Li, Bor-Ran
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Li, Yaw-Kuen
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交大名義發表
We report a peptide-based sensor that involves a multivalent interaction with L-ascorbate 6-phosphate lactonase (UlaG), a protein marker of Streptococcus pneumonia. By integrating the antifouling feature of the sensor, we significantly improved the signal-to-noise ratio of UlaG detection. The antifouling surface was fabricated via electrodeposition using an equivalent mixture of 4-amino-N,N,N-trimethylanilinium and 4-aminobenzenesulfonate. This antifouling layer not only effectively reduces the non-specific adsorption on the biosensor but also decreases the charge transfer resistance (R-et) of the screen-printed carbon electrode. The aniline-modified 57 peptide, an UlaG-binding peptide, was pre-synthesized and further electrochemically modified to bind onto the antifouling layer. Bio-electrochemical analysis confirms that the antifouling 57-peptide sensor binds strongly to the UlaG with a dissociation constant (K-d) = 0.5 nM. This strong interaction can be attributed to a multivalent interaction between the biosensor and the heximeric form of UlaG. To demonstrate the potential for clinical application, further detection of Streptococcus pneumonia from 50 to 5 x 10(4) CFU/mL were successfully performed in 25% human serum.
An L-ascorbate-6-phosphate lactonase from Streptococcus pneumoniae ATCC 49136 strain reveals metallo-beta-lactamase activity
(2016-05)
Chang, Chia-Yu
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Li, Bor-Ran
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Li, Yaw-Kuen
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分子醫學與生物工程研究所
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應用化學系
Antifouling strategies in advanced electrochemical sensors and biosensors
(2020-02-21)
Lin, Pei-Heng
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Li, Bor-Ran
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交大名義發表
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National Chiao Tung University
Electrochemical biosensors have been applied in a broad range of clinical applications for pathogen biomarker detection and medical applications and diagnosis due to the sensitivity of electrochemical methods and the bioselectivity of the components. The complexity of clinical conditions with various biofoulants (proteins, cells, polysaccharides and lipids) severely influences the reliability and stability of sensors for direct detection or immersion under changing conditions. Therefore, designing an antifouling sensing platform that can effectively reduce undesired binding to maintain biosensor performance in optimized analysis is necessary. For this purpose, the fundamental mechanisms of fouling materials and commonly used biocompatible antifouling components have been discussed, and the relevant effective modification strategies are introduced in this review. Recent advances in these strategies are demonstrated in examples with analysis of essential modification methods for reliable sensing in non-specific binding solutions or complex biofluids. The challenges and future perspectives of modification strategies for current clinical application are also discussed in this review.
Effective Construction of a High-Capacity Boronic Acid Layer on a Quartz Crystal Microbalance Chip for High-Density Antibody Immobilization
(2019-01-01)
Lin, Pei-Heng
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Huang, Sheng-Cih
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Chen, Kuang-Po
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Li, Bor-Ran
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Li, Yaw-Kuen
Boronic acids (BAs) provide strong potential in orientation immobilization of antibody and the modification method is crucial for efficiency optimization. A highly effective method has been developed for rapid antibody immobilization on gold electrodes through the electrodeposition of a BA-containing linker in this study. Aniline-based BA forms a condense layer while antibody could automatically immobilize on the surface of the electrode. Compare to traditional self-assembled monolayer method, the electrodeposition process dramatically reduces the modification time from days to seconds. It also enhances the immobilized efficiency from 95 to 408 (ng/cm(2)) with a strong preference being exhibited for shorter aniline-based linkers.
Fabrication of magnetic liquid marbles using superhydrophobic atmospheric pressure plasma jet-formed fluorinated silica nanocomposites
(2019-07-01)
Wu, She-Ting
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Weng, Chih-Chiang
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Li, Bor-Ran
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Hsu, Chain-Shu
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交大名義發表
In this study, the surface properties of iron microparticles were modified for the manipulation of liquid droplets using atmospheric pressure plasma jets. These modified hydrophobic iron microparticles were prepared by synthesizing fluorinated silica nanocomposites on the surfaces of iron microparticles under atmospheric pressure plasma. The compositions of the silica nanocomposites were controlled by the deposition of hexamethyldisiloxane and fluoroalkylsilane precursors. The fluorinated silica nanocomposites were then used with iron microparticles to prepare magnetic liquid marbles. The contact angles of the iron microparticles and the fluorinated silica nanoparticle coating on the glass surface were both 154 degrees, which indicated that the surfaces of these particles were superhydrophobic. Higher hexamethyldisiloxane precursor flow rates produced more silica nanocomposites and resulted in greater roughness and larger contact angles. Changes in surface roughness were characterized by atomic force microscopy. X-ray photoelectron spectroscopy showed that C-F bonds were present on the modified glass surface. The presented approach allows rapid and highly efficient modification of uneven surfaces and can therefore be employed to render hydrophilic, superhydrophobic, and oleophilic surfaces. Moreover, the described hydrophobic iron microparticles can be used for the controlled magnetic manipulation of water droplets and oil-water separation.
Hand-powered centrifugal microfluidic disc with magnetic chitosan bead-based ELISA for antibody quantitation
(2020-08-01)
Lin, Chia-Tung
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Kuo, Shao-Hsuan
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Lin, Pei-Heng
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Chiang, Pei-Huan
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Lin, Wan-Hsuan
Extreme point-of-care testing (POCT) is a medical test performed at or near patients at a resource-limited condition. POCT technology has advantages over traditional medical lab tests for molecular detection and infection diagnosis, such as being simple, portable, low-cost, and user-friendly. However, some POCT devices might rely on bulky equipment, and some might be easily influenced by components in biofluid, which might result in higher prices and lower accuracy. In this paper, we demonstrated a low-cost method for detecting bacterial infection in the early stage. We designed a hand-powered centrifugal microfluidic (CMF) disc with magnetic chitosan beads (MCBs) to detect specific circulating antibodies in human whole blood. Nine identical units was used for calibration curve plotting and sample testing. The MCBs, generated with another microfluidic chip and coated with MBL proteins (biomarker of drug-resistant Streptococcus pneumoniae, DRSP, taken as an example for bacterial infection), were served as the substrate of sandwich-structured enzyme-linked immunosorbent assays (ELISA) and as the micro stirring sphere at the same time. The limit of detection (LOD) in PBS and human whole blood were 22.67 ng/mL and 24.83 ng/mL, respectively. The comparison between calibration curves from the antibody spiked in human whole blood and that in PBS was shown to prove the high compatibility and low interference of biofluid, and the recovery rate was 92 %. In conclusion, since our low-cost, time-saving, and user-friendly hand-powered CMF device with minimally consumed electricity detected the target antibody precisely, we believe that other similar assays would be feasible as well. Therefore, we are firmly convinced that this alternative POCT device may lead to the development of next-generation healthcare diagnoses.
Noninvasive Glucose Monitoring with a Contact Lens and Smartphone
(2018-10-01)
Lin, You-Rong
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Hung, Chin-Chi
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Chiu, Hsien-Yi
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Chang, Po-Han
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Li, Bor-Ran
Diabetes has become a chronic metabolic disorder, and the growing diabetes population makes medical care more important. We investigated using a portable and noninvasive contact lens as an ideal sensor for diabetes patients whose tear fluid contains glucose. The key feature is the reversible covalent interaction between boronic acid and glucose, which can provide a noninvasive glucose sensor for diabetes patients. We present a phenylboronic acid (PBA)-based HEMA contact lens that exhibits a reversible swelling/shrinking effect to change its thickness. The difference in thickness can be detected in a picture taken with a smartphone and analyzed using software. Our novel technique offers the following capabilities: (i) non-enzymatic and continuous glucose detection with the contact lens; (ii) no need for an embedded circuit and power source for the glucose sensor; and (iii) the use of a smartphone to detect the change in thickness of the contact lens with no need for additional photo-sensors. This technique is promising for a noninvasive measurement of the glucose level and simple implementation of glucose sensing with a smartphone.
Rapid and Safe Isolation of Human Peripheral Blood B and T Lymphocytes through Spiral Microfluidic Channels
(2019-05-31)
Chiu, Po-Lin
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Chang, Chun-Hao
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Lin, Yu-Ling
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Tsou, Ping-Hsien
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Li, Bor-Ran
Peripheral blood lymphocytes (PBLs) are mature lymphocytes that circulate in the blood rather than being localized to organs. A reliable label-free collection approach that can viably and appropriately isolate PBLs to establish in vitro culture systems is crucial for basic research and clinical requirements. However, isolation of PBLs from whole blood is difficult, and so the development of a rapid and safe method to perform this task is required. Microfluidic technology offers opportunities that challenge the performance of macroscale methods. In this study, we proposed a simple spiral microfluidic chip for efficient and high-throughput isolation of lymphocytes from a sample with prelysed RBCs. This spiral microfluidic platform does not rely on antibodies or biological markers for labeling cells of interest while isolating lymphocytes but rather enriches B and T lymphocytes through the different physical properties that are intrinsic to lymphocytes and other blood cells. The device was used to achieve high-throughput (similar to 1.3 x 10(5) cells/min) separation of lymphocytes with high viability (>95%). Compared with previous approaches, our device provided rapid, label-free, high-throughput, and safe lymphocyte separation.
Rapid construction of an effective antifouling layer on a Au surface via electrodeposition
(2014)
Li, Bor-Ran
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Shen, Mo-Yuan
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Yu, Hsiao-Hua
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Li, Yaw-Kuen
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應用化學系
A new approach to immobilize zwitterionic molecules rapidly and highly efficiently on a gold surface applies aniline-based electro-deposition. The zwitterion-functionalized antifouling surface enables a decrease of the adsorption of non-specific proteins by 95% from fetal bovine serum (FBS, 10%).
Rapid Prototyping of an Open-Surface Microfluidic Platform Using Wettability-Patterned Surfaces Prepared by an Atmospheric-Pressure Plasma Jet
(2019-10-08)
Wu, She-Ting
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Huang, Chen-Yu
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Weng, Chih-Chiang
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Chang, Chia-Chih
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Li, Bor-Ran
Open-surface microfluidics is promising in terms of enabling economical and rapid biochemical analysis for addressing challenges associated with medical diagnosis and food safety. To this end, we present a simple and economical approach to develop an open-surface microfluidic platform suitable for facile liquid transport and mixing. Customizable patterns with tailored wettability are deposited using a plasma-assisted deposition technique under atmospheric pressure. The flow of the dispensed liquid is driven by gravity, and the tilting angle of the device determines the extent of mixing. First, a hexamethyldisiloxane film was deposited to create hydrophobic patterns on glass, and then, hydrophilic acrylic acid was deposited by a patterned cardboard mask to construct a channel suitable for forming channels to transport aqueous liquids without the need of an external energy input; the liquid can be confined to designated pathways. Several designs including Y-junctions, serpentine-shaped patterns, splitting channels, and concentration gradient generation patterns are presented. The proposed method can spatially pattern a surface with a hydrophobic/hydrophilic area, which can function as a microfluidic channel, and the surface can be applied in microfluidic devices with other types of substrates.
Silicon nanowire field-effect-transistor based biosensors: From sensitive to ultra-sensitive
(2014-10-15)
Shen, Mo-Yuan
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Li, Bor-Ran
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Li, Yaw-Kuen
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應用化學系
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Department of Applied Chemistry
Silicon nanowire field effect transistors (SiNW-FETs) have shown great promise as biosensors in highly sensitive, selective, real-time and label-free measurements. While applications of SiNW-FETs for detection of biological species have been described in several publications, less attention has been devoted to summarize the conjugating methods involved in linking organic bio-receptors with the inorganic transducer and the strategies of improving the sensitivity of devices. This article attempts to focus on summarizing the various organic immobilization approaches and discussing various sensitivity improving strategies, that include (I) reducing non-specific binding, (II) alignment of the probes, (III) enhancing signals by charge reporter, (IV) novel architecture structures, and (V) sensing in the subthreshold regime. (C) 2014 Elsevier B.V. All rights reserved.
Thermopneumatic suction integrated microfluidic blood analysis system
(2019-03-07)
Yang, Chiao-Hsun
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Hsieh, Yu-Ling
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Tsou, Ping-Hsien
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Li, Bor-Ran
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交大名義發表
Blood tests provide crucial diagnostic information regarding several diseases. A key factor that affects the precision and accuracy of blood tests is the interference of red blood cells; however, the conventional methods of blood separation are often complicated and time consuming. In this study, we devised a simple but high-efficiency blood separation system on a self-strained microfluidic device that separates 99.7 +/- 0.3% of the plasma in only 6 min. Parameters, such as flow rate, design of the filter trench, and the relative positions of the filter trench and channel, were optimized through microscopic monitoring. Moreover, this air difference-driven device uses a cost-effective and easy-to-use heater device that creates a low-pressure environment in the microchannel within minutes. With the aforementioned advantages, this blood separation device could be another platform choice for point-of-care testing.