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Yang C, Gan X, Zeng Y, Xu Z, Xu L, Hu C, Ma H, Chai B, Hu S, Chai Y. Advanced design and applications of digital microfluidics in biomedical fields: An update of recent progress. Biosens Bioelectron 2023; 242:115723. [PMID: 37832347 DOI: 10.1016/j.bios.2023.115723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 09/11/2023] [Accepted: 09/29/2023] [Indexed: 10/15/2023]
Abstract
Significant breakthroughs have been made in digital microfluidic (DMF)-based technologies over the past decades. DMF technology has attracted great interest in bioassays depending on automatic microscale liquid manipulations and complicated multi-step processing. In this review, the recent advances of DMF platforms in the biomedical field were summarized, focusing on the integrated design and applications of the DMF system. Firstly, the electrowetting-on-dielectric principle, fabrication of DMF chips, and commercialization of the DMF system were elaborated. Then, the updated droplets and magnetic beads manipulation strategies with DMF were explored. DMF-based biomedical applications were comprehensively discussed, including automated sample preparation strategies, immunoassays, molecular diagnosis, blood processing/testing, and microbe analysis. Emerging applications such as enzyme activity assessment and DNA storage were also explored. The performance of each bioassay was compared and discussed, providing insight into the novel design and applications of the DMF technology. Finally, the advantages, challenges, and future trends of DMF systems were systematically summarized, demonstrating new perspectives on the extensive applications of DMF in basic research and commercialization.
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Affiliation(s)
- Chengbin Yang
- School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen, China.
| | - Xiangyu Gan
- School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen, China.
| | - Yuping Zeng
- School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen, China.
| | - Zhourui Xu
- School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen, China.
| | - Longqian Xu
- CAS Key Laboratory of Bio-Medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, China.
| | - Chenxuan Hu
- CAS Key Laboratory of Bio-Medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, China.
| | - Hanbin Ma
- CAS Key Laboratory of Bio-Medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, China; Guangdong ACXEL Micro & Nano Tech Co., Ltd, Foshan, China.
| | - Bao Chai
- Department of Dermatology, Huazhong University of Science and Technology Union Shenzhen Hospital, Shenzhen, China; Department of Dermatology, The 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China.
| | - Siyi Hu
- CAS Key Laboratory of Bio-Medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, China.
| | - Yujuan Chai
- School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen, China.
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Tong Z, Shen C, Li Q, Yin H, Mao H. Combining sensors and actuators with electrowetting-on-dielectric (EWOD): advanced digital microfluidic systems for biomedical applications. Analyst 2023; 148:1399-1421. [PMID: 36752059 DOI: 10.1039/d2an01707e] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
The concept of digital microfluidics (DMF) enables highly flexible and precise droplet manipulation at a picoliter scale, making DMF a promising approach to realize integrated, miniaturized "lab-on-a-chip" (LOC) systems for research and clinical purposes. Owing to its simplicity and effectiveness, electrowetting-on-dielectric (EWOD) is one of the most commonly studied and applied effects to implement DMF. However, complex biomedical assays usually require more sophisticated sample handling and detection capabilities than basic EWOD manipulation. Alternatively, combined systems integrating EWOD actuators and other fluidic handling techniques are essential for bringing DMF into practical use. In this paper, we briefly review the main approaches for the integration/combination of EWOD with other microfluidic manipulation methods or additional external fields for specified biomedical applications. The form of integration ranges from independently operating sub-systems to fully coupled hybrid actuators. The corresponding biomedical applications of these works are also summarized to illustrate the significance of these innovative combination attempts.
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Affiliation(s)
- Zhaoduo Tong
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China. .,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chuanjie Shen
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China. .,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qiushi Li
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
| | - Hao Yin
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China. .,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hongju Mao
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
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Lee MS, Chang YC, Huang HY, Hsu W. Single-type Reporter Multiplexing with A Single Droplet Through Bead-based Digital Microfluidics. J Pharm Biomed Anal 2022; 219:114877. [DOI: 10.1016/j.jpba.2022.114877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 04/19/2022] [Accepted: 05/09/2022] [Indexed: 11/24/2022]
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Bead Number Effect in a Magnetic-Beads-Based Digital Microfluidic Immunoassay. BIOSENSORS 2022; 12:bios12050340. [PMID: 35624641 PMCID: PMC9138409 DOI: 10.3390/bios12050340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 05/11/2022] [Accepted: 05/13/2022] [Indexed: 11/17/2022]
Abstract
In a biomedical diagnosis with a limited sample volume and low concentration, droplet-based microfluidics, also called digital microfluidics, becomes a very attractive approach. Previously, our group developed a magnetic-beads-based digital microfluidic immunoassay with a bead number of around 100, requiring less than 1 μL of sample volume to achieve a pg/mL level limit of detection (LOD). However, the bead number in each measurement was not the same, causing an unstable coefficient of variation (CV) in the calibration curve. Here, we investigated whether a fixed number of beads in this bead-based digital microfluidic immunoassay could provide more stable results. First, the bead screening chips were developed to extract exactly 100, 49, and 25 magnetic beads with diameters of less than 6 μm. Then, four calibration curves were established. One calibration curve was constructed by using varying bead numbers (50–160) in the process. The other three calibration curves used a fixed number of beads, (100, 49, and 25). The results indicated that the CVs for a fixed number of beads were evidently smaller than the CVs for varying bead numbers, especially in the range of 1 pg/mL to 100 pg/mL, where the CVs for 100 beads were less than 10%. Furthermore, the calculated LOD, based on the composite calibration curves, could be reduced by three orders, from 3.0 pg/mL (for the unfixed bead number) to 0.0287 pg/mL (for 100 beads). However, when the bead numbers were too high (more than 500) or too low (25 or fewer), the bead manipulation for aggregation became more difficult in the magnetic-beads-based digital microfluidic immunoassay chip.
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Juang DS, Lang JM, Beebe DJ. Volumeless reagent delivery: a liquid handling method for adding reagents to microscale droplets without increasing volume. LAB ON A CHIP 2022; 22:286-295. [PMID: 34897347 PMCID: PMC8820037 DOI: 10.1039/d1lc00906k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The addition of reagents for assays in digital microfluidic (DMF) systems is traditionally done by merging of droplets containing different analytes or reagents in solution. However, this process significantly increases droplet volume after each step, resulting in dilution of the analyte and reagents. Here, we report a new technique for performing reagent additions to aqueous droplets without significantly increasing the droplet's volume: volume-less reagent delivery (VRD). VRD is enabled by a physical phenomenon we call "exclusive liquid repellency" (ELR), which describes an aqueous/oil/solid 3-phase system where the aqueous phase can be fully repelled from a solid phase (contact angle ∼180°). When performing VRD, a reagent of interest in solution is deposited onto the ELR solid surface and allowed to dry. The ELR surface containing the dried reagent is then immersed under oil, followed by introduction of an aqueous droplet. By dragging the aqueous droplet over the spot of dried reagent using paramagnetic particles or via a physical sliding wall, the droplet can then recover and reconstitute the reagent with negligible increase in its total volume, returning the ELR surface to its initial liquid repellent state in the process. We demonstrate that VRD can be performed across a wide range of reagent types including sugars, proteins (antibodies), nucleic acids (DNA), antibiotics, and even complex enzyme/substrate/buffer "kit" mixtures. We believe VRD is a flexible and powerful technique which can further the development of self-contained, multi-step assays in DMF and other microfluidic systems.
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Affiliation(s)
- Duane S Juang
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53705, USA.
| | - Joshua M Lang
- Department of Medicine, Wisconsin Institutes for Medical Research, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - David J Beebe
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53705, USA.
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA
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Guo J, Lin L, Zhao K, Song Y, Huang M, Zhu Z, Zhou L, Yang C. Auto-affitech: an automated ligand binding affinity evaluation platform using digital microfluidics with a bidirectional magnetic separation method. LAB ON A CHIP 2020; 20:1577-1585. [PMID: 32207498 DOI: 10.1039/d0lc00024h] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The dissociation constant (Kd) is a crucial parameter for characterizing binding affinity in molecular recognition, including antigen-antibody, DNA-protein, and receptor-ligand interactions. However, conventional methods for Kd characterization usually involve a multi-step process and time-consuming operations for incubation, washing, and detection, thus causing problems, such as time delays, microbead loss, degradation of sensitive molecules, and personal errors. Here we demonstrate an automated ligand binding affinity evaluation platform (Auto-affitech) using digital microfluidics (DMF), with individual droplets at the microliter level, programmed to rapidly perform the incubation and separation of target-beads and binding ligands. Because the loss of the beads influences the detection results, we propose a new strategy for magnetic bead separation using DMF, termed the bidirectional separation method. By splitting one droplet into two asymmetric droplets, high bead retention efficiency (89.57% ± 0.05%) and high washing efficiency (99.59% ± 0.17%, with four washings) were obtained. We demonstrate the determination of Kd of an aptamer-protein system (EpCAM and its corresponding aptamer SYL3C) and an antigen-antibody system (H5N1 antigen and antibody), proving the capability and universality of Auto-affitech in various receptor-ligand systems. Integrating all the sample processing procedures, the Auto-affitech not only saves manual labor and minimizes personal errors, but also conserves samples and shortens analysis time. Overall, this platform successfully demonstrates to be an automated approach for dissociation constant evaluation and exhibits great potential for highly efficient screening of ligands.
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Affiliation(s)
- Jingjing Guo
- MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Key Laboratory of Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
| | - Li Lin
- MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Key Laboratory of Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
| | - Kaifeng Zhao
- MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Key Laboratory of Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
| | - Yanling Song
- Institute of Molecular Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Mengjiao Huang
- MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Key Laboratory of Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
| | - Zhi Zhu
- MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Key Laboratory of Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
| | - Leiji Zhou
- MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Key Laboratory of Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
| | - Chaoyong Yang
- MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Key Laboratory of Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China. and Institute of Molecular Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China
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Ruvalcaba-Cardenas AD, Gomez RAR, Khoshmanesh K, Tovar-Lopez FJ. Magnetic actuation and deformation of a soft shuttle. BIOMICROFLUIDICS 2020; 14:034103. [PMID: 32477442 PMCID: PMC7237223 DOI: 10.1063/5.0008176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 05/05/2020] [Indexed: 05/12/2023]
Abstract
Here, we describe the magnetic actuation of soft shuttles for open-top microfluidic applications. The system is comprised of two immiscible liquids, including glycerol as the soft shuttle and a suspension of iron powder in sucrose solution as the magnetic drop. Permanent magnets assembled on 3D printed motorized actuators were used for the actuation of the magnetic drop, enabling the glycerol shuttle to be propelled along customized linear, circular, and sinusoidal paths. The dynamics of the hybrid shuttle-magnetic drop system was governed by the magnetic force, the friction at the interface of the shuttle and the substrate, and the surface tension at the interface of the shuttle and the magnetic drop. Increasing the magnetic force leads to the localized deformation of the shuttle and eventually the full extraction of the magnetic drop. The versatility of the system was demonstrated through the propelling of the shuttle across a rough surface patterned with microfabricated barriers as well as taking advantage of the optical properties of the shuttle for the magnification and translation of microscale characters patterned on a planar surface. The integration of the system with current electrowetting actuation mechanisms enables the highly controlled motion of the magnetic drop on the surface of a moving shuttle. The simplicity, versatility, and controllability of the system provide opportunities for various fluid manipulation, sample preparation, and analysis for a range of chemical, biochemical, and biological applications.
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Affiliation(s)
- Ana Daysi Ruvalcaba-Cardenas
- School of Engineering, RMIT University, Melbourne, Victoria 3000, Australia
- Authors to whom correspondence should be addressed:; ; and
| | | | - Khashayar Khoshmanesh
- School of Engineering, RMIT University, Melbourne, Victoria 3000, Australia
- Authors to whom correspondence should be addressed:; ; and
| | - Francisco J. Tovar-Lopez
- School of Engineering, RMIT University, Melbourne, Victoria 3000, Australia
- Authors to whom correspondence should be addressed:; ; and
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Lee MS, Hsu W, Huang HY, Tseng HY, Lee CT, Hsu CY, Shieh YC, Wang SH, Yao DJ, Liu CH. Simultaneous detection of two growth factors from human single-embryo culture medium by a bead-based digital microfluidic chip. Biosens Bioelectron 2019; 150:111851. [PMID: 31740257 DOI: 10.1016/j.bios.2019.111851] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 10/31/2019] [Accepted: 11/05/2019] [Indexed: 12/30/2022]
Abstract
The measurement of growth factors released in a culture medium is considered to be an attractive non-invasive approach, apart from the embryo morphology, to identify the condition of an embryo development after fertilization in vitro (IVF), but the available embryo culture medium in the current method is only a few microlitres. This small sample volume, also of small concentration, makes difficult the application of a conventional detection method, such as an enzyme-linked immunosorbent assay (ELISA). A reliable detection of the growth factor from each embryo culture medium of such a small concentration hence remains a challenge. Here for the first time we report the results of measurement of not just one, but two, growth factors, human IL-1β and human TNF-α, from an individual droplet of embryo culture medium with a bead-based digital microfluidic chip. The required sample volume for a single measurement is only 520 nL; the total duration of the on-chip process is less than 40 min. Using the culture media of human embryos with normal morphologic features, we found that the concentrations of TNF-α change little from day 3 to day 5-6, but the concentrations of IL-1β for some embryos might double from day 3 to day 5-6. For other embryos even with similar normal morphologic features, some growth factors, such as IL-1β, might exhibit different expressions during the culture period. Those growth factors could serve to distinguish the development conditions of each embryo, not merely from an observation of embryo morphology.
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Affiliation(s)
- Meng-Shiue Lee
- Department of Mechanical Engineering, National Chiao Tung University, Hsinchu, Taiwan
| | - Wensyang Hsu
- Department of Mechanical Engineering, National Chiao Tung University, Hsinchu, Taiwan.
| | - Hong-Yuan Huang
- Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital, Tao-Yuan, Taiwan; Department of Obstetrics and Gynecology, Chang Gung University College of Medicine, Tao-Yuan, Taiwan.
| | - Hsueh-Yang Tseng
- Department of Mechanical Engineering, National Chiao Tung University, Hsinchu, Taiwan
| | - Chia-Tung Lee
- Department of Mechanical Engineering, National Chiao Tung University, Hsinchu, Taiwan
| | - Chung-Yu Hsu
- Department of Mechanical Engineering, National Chiao Tung University, Hsinchu, Taiwan
| | - Yi-Chueh Shieh
- Department of Mechanical Engineering, National Chiao Tung University, Hsinchu, Taiwan
| | - Shih-Hung Wang
- Department of Mechanical Engineering, National Chiao Tung University, Hsinchu, Taiwan
| | - Da-Jeng Yao
- Institute of Nanoengineering and Microsystem, National Tsing Hua University, Hsinchu, Taiwan; Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu, Taiwan
| | - Cheng-Hsien Liu
- Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu, Taiwan
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Development of Coplanar Electro-Wetting Based Microfluidic Sorter to Select Micro-Particles in High Volume Throughput at Milliliter Amount within Twenty Minutes. SENSORS 2018; 18:s18092941. [PMID: 30181484 PMCID: PMC6164432 DOI: 10.3390/s18092941] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Revised: 08/28/2018] [Accepted: 09/01/2018] [Indexed: 11/17/2022]
Abstract
This paper reports the work of developing one coplanar microfluidic sorter while using the electro-wetting on dielectrics (EWOD) technique. When connected with delivery capillary to receive sample solution containing micro-particles, this device can select about 10 micro-particles in high volume throughput of milliliter amount within 20 min, to potentially match the requirement of efficiently determining the low amounts of bacteria in concentrated food and environmental samples, of which the typical bacteria density is 10 colony forming unit or less, much smaller than that of clinical pathogen samples. This coplanar T-shape EWOD device contains two fluidic channels, one inlet channel and the other collection channel stemmed from the middle of inlet channel. When the solution droplet falls from the delivery capillary to the entrance end of inlet channel, the droplet is driven to the intersection of two channels. The droplet containing fluorescent particle will be diverted to the lower channel to collect. Otherwise, the non-fluorescent droplet keeps moving toward the other end of inlet channel to waste zone. The particle fluorescence is collected through microscope lens to detect with one photomultiplier tube. The detected signals trigger the personal computer control board to active each EWOD electrode to direct the droplet moving directions. When the solution of 1 mL containing about 10 fluorescent micro-particles is delivered into this sorting device, nearly all the particles were correctly directed into collection zone in 20 min.
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Abstract
A digital microfluidic platform manipulates droplets on an open surface. Magnetic digital microfluidics utilizes magnetic forces for actuation and offers unique advantages compared to other digital microfluidic platforms. First, the magnetic particles used in magnetic digital microfluidics have multiple functions. In addition to serving as actuators, they also provide a functional solid substrate for molecule binding, which enables a wide range of applications in molecular diagnostics and immunodiagnostics. Second, magnetic digital microfluidics can be manually operated in a "power-free" manner, which allows for operation in low-resource environments for point-of-care diagnostics where even batteries are considered a luxury item. This review covers research areas related to magnetic digital microfluidics. This paper first summarizes the current development of magnetic digital microfluidics. Various methods of droplet manipulation using magnetic forces are discussed, ranging from conventional magnetic particle-based actuation to the recent development of ferrofluids and magnetic liquid marbles. This paper also discusses several new approaches that use magnetically controlled flexible substrates for droplet manipulation. In addition, we emphasize applications of magnetic digital microfluidics in biosensing and medical diagnostics, and identify the current limitations of magnetic digital microfluidics. We provide a perspective on possible solutions to close these gaps. Finally, the paper discusses the future improvement of magnetic digital microfluidics to explore potential new research directions.
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Affiliation(s)
- Yi Zhang
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore.
| | - Nam-Trung Nguyen
- Queensland Micro- and Nanotechnology Centre, Griffith University, Brisbane, QLD 4111, Australia
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Wang G, Das C, Ledden B, Sun Q, Nguyen C, Kumar S. Evaluation of disposable microfluidic chip design for automated and fast Immunoassays. BIOMICROFLUIDICS 2017; 11:014115. [PMID: 28344726 PMCID: PMC5325810 DOI: 10.1063/1.4977198] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 02/10/2017] [Indexed: 05/08/2023]
Abstract
We report here, the design and development of a disposable immunoassay chip for protein biomarker detection within ∼1 h. The unique design allows for real-time dynamic calibration of immunoassay for multiple biomarker detections on the chip. The limit of detection achieved for this test chip is 10 pg/ml for IL6, and 50 pg/ml for GFAP with a detection time of 1 h. The prototype instrument used for flowing the reagents through the chip can be easily assembled from off-the-shelf components with the final chemiluminescent detection carried out in a commercial plate reader. Optimization of different aspects of chip design, fabrication, and assay development is discussed in detail.
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Affiliation(s)
- Guochun Wang
- SFC Fluidics, Inc. , Fayetteville, Arkansas 72701, USA
| | - Champak Das
- SFC Fluidics, Inc. , Fayetteville, Arkansas 72701, USA
| | | | - Qian Sun
- SFC Fluidics, Inc. , Fayetteville, Arkansas 72701, USA
| | - Chien Nguyen
- SFC Fluidics, Inc. , Fayetteville, Arkansas 72701, USA
| | - Sai Kumar
- Diligent CXO , Norcross, Georgia 30071, USA
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Lee H, Lim S, Birajdar MS, Lee SH, Park H. Fabrication of FGF-2 immobilized electrospun gelatin nanofibers for tissue engineering. Int J Biol Macromol 2016; 93:1559-1566. [PMID: 27426702 DOI: 10.1016/j.ijbiomac.2016.07.041] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 07/11/2016] [Accepted: 07/13/2016] [Indexed: 12/14/2022]
Abstract
Conjugated gelatin nanofibers were fabricated by electrospinning, followed by a simple glutaraldehyde cross-linking procedure and avidin conjugation. Then, biotinylated growth factors were immobilized onto the surface of the fibers through avidin-biotin covalent binding. The immobilization of growth factors was confirmed through immunostaining using fluorescence microscopy and microplate spectrophotometry. Adipose derived stem cells (ASCs) were cultured to examine the effect of immobilized growth factors on cell proliferation using the cell counting Kit-8 (CCK-8) assay. Gelatin nanofibers with no growth factors attached and growth factors in suspension within media were used as controls. Growth factors were successfully immobilized onto the surface, in amounts corresponding to the concentrations applied, and increased cell proliferation to a higher extend than growth factors in suspension. Our results suggest that this controllable scaffolding strategy provides an effective system for growth factors delivery in tissues, suitable for engineering applications.
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Affiliation(s)
- Haram Lee
- School of Integrative Engineering, Chung-Ang University, Republic of Korea
| | - Sooseok Lim
- School of Integrative Engineering, Chung-Ang University, Republic of Korea
| | | | - Soo-Hong Lee
- Department of Biomedical Science, College of Life Science, CHA University, Republic of Korea.
| | - Hansoo Park
- School of Integrative Engineering, Chung-Ang University, Republic of Korea.
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Samiei E, Tabrizian M, Hoorfar M. A review of digital microfluidics as portable platforms for lab-on a-chip applications. LAB ON A CHIP 2016; 16:2376-96. [PMID: 27272540 DOI: 10.1039/c6lc00387g] [Citation(s) in RCA: 195] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Following the development of microfluidic systems, there has been a high tendency towards developing lab-on-a-chip devices for biochemical applications. A great deal of effort has been devoted to improve and advance these devices with the goal of performing complete sets of biochemical assays on the device and possibly developing portable platforms for point of care applications. Among the different microfluidic systems used for such a purpose, digital microfluidics (DMF) shows high flexibility and capability of performing multiplex and parallel biochemical operations, and hence, has been considered as a suitable candidate for lab-on-a-chip applications. In this review, we discuss the most recent advances in the DMF platforms, and evaluate the feasibility of developing multifunctional packages for performing complete sets of processes of biochemical assays, particularly for point-of-care applications. The progress in the development of DMF systems is reviewed from eight different aspects, including device fabrication, basic fluidic operations, automation, manipulation of biological samples, advanced operations, detection, biological applications, and finally, packaging and portability of the DMF devices. Success in developing the lab-on-a-chip DMF devices will be concluded based on the advances achieved in each of these aspects.
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Affiliation(s)
- Ehsan Samiei
- School of Engineering, University of British Columbia, 3333 University Way, Kelowna, BC V1V 1V7, Canada.
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Fan SK, Yang Z. Preface to Special Topic: Selected Papers from the 5th International Conference on Optofluidics. BIOMICROFLUIDICS 2016; 10:011701. [PMID: 27076863 PMCID: PMC4818270 DOI: 10.1063/1.4942611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 02/11/2016] [Indexed: 06/05/2023]
Abstract
The 5th International Conference on Optofluidics (Optofluidics 2015) was held in Taipei, Taiwan, July 26-29, 2015. The aim of this conference was to provide a forum to promote scientific exchange and to foster closer networks and collaborative ties between leading international researchers in optics and micro/nanofluidics across various disciplines. The scope of Optofluidics 2015 was deliberately broad and interdisciplinary, encompassing the latest advances and the most innovative developments in micro/nanoscale science and technology. Topics ranged from fundamental research to its applications in chemistry, physics, biology, materials, and medicine.
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Affiliation(s)
- Shih-Kang Fan
- Department of Mechanical Engineering, National Taiwan University , Taipei, Taiwan
| | - Zhenchuan Yang
- Institute of Microelectronics, Peking University , Beijing, China
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