Michael J Rupar, Hannah Hanson, Stephanie Rogers, Brianna Botlick, Steven Trimmer, James J Hickman
This critical review aims to highlight how modeling of the immune response has adapted over time to utilize microphysiological systems. Topics covered here will discuss the integral components of the immune system in various human body systems, and how these interactions are modeled using these systems. Through the use of microphysiological systems, we have not only expanded on foundations of basic immune cell information, but have also gleaned insight on how immune cells work both independently and collaboratively within an entire human body system.
{"title":"Modelling the innate immune system in microphysiological systems.","authors":"Michael J Rupar, Hannah Hanson, Stephanie Rogers, Brianna Botlick, Steven Trimmer, James J Hickman","doi":"10.1039/d3lc00812f","DOIUrl":"https://doi.org/10.1039/d3lc00812f","url":null,"abstract":"<p><p>This critical review aims to highlight how modeling of the immune response has adapted over time to utilize microphysiological systems. Topics covered here will discuss the integral components of the immune system in various human body systems, and how these interactions are modeled using these systems. Through the use of microphysiological systems, we have not only expanded on foundations of basic immune cell information, but have also gleaned insight on how immune cells work both independently and collaboratively within an entire human body system.</p>","PeriodicalId":85,"journal":{"name":"Lab on a Chip","volume":null,"pages":null},"PeriodicalIF":6.1,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141490046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pierre Dedieu, Gabriel Morand, Karine Loubière, Stéphanie Ognier, Michael Tatoulian
Microreactors were designed for gas-liquid plasma chemical processes and operated under segmented flows in a high aspect ratio (8.76) rectangular microchannel. First, the hydrodynamics of the gas-liquid flows generated at a T-junction was investigated for fifteen solvents commonly used in organic synthesis. The classical literature scaling laws were revised to describe the dependence of bubble and slug lengths, and bubble residence time on the liquid nature by introducing their liquid vapour pressure. Liquid film thickness and liquid residence time were estimated from residence time distribution experiments. Secondly, plasma could be successfully generated in these segmented flows for all the liquids. Due to the plasma dissipation of thermal energy, gas phase temperature increased and induced the lengthening of bubbles and the decrease in bubble residence time. Flow pattern was also impacted by the gas temperature increase. A flow map describing the evolution of flow pattern under plasma conditions was built, enabling prediction of the flow pattern based on liquid boiling point and dielectric constant. These microreactors have demonstrated great potential, and by adapting the synthesis solvent or the operating plasma conditions, they could find promising applications in gas-liquid plasma chemical processes.
设计了用于气液等离子化学过程的微反应器，并在高纵横比（8.76）矩形微通道中的分段流下运行。首先，针对有机合成中常用的 15 种溶剂，研究了 T 型交界处产生的气液流的流体力学。通过引入液体蒸汽压，对经典文献的缩放定律进行了修订，以描述气泡和蛞蝓长度以及气泡停留时间对液体性质的依赖性。根据停留时间分布实验估算了液膜厚度和液体停留时间。其次，所有液体都能在这些分段流中成功产生等离子体。由于等离子体耗散热能，气相温度升高，导致气泡延长，气泡停留时间缩短。流动模式也受到气体温度升高的影响。我们绘制了等离子条件下流动模式演变的流动图，从而能够根据液体沸点和介电常数预测流动模式。这些微反应器显示出巨大的潜力，通过调整合成溶剂或操作等离子条件，它们在气液等离子化学过程中的应用前景广阔。
{"title":"Microreactor designed for efficient plasma-liquid segmented flows","authors":"Pierre Dedieu, Gabriel Morand, Karine Loubière, Stéphanie Ognier, Michael Tatoulian","doi":"10.1039/d4lc00315b","DOIUrl":"https://doi.org/10.1039/d4lc00315b","url":null,"abstract":"Microreactors were designed for gas-liquid plasma chemical processes and operated under segmented flows in a high aspect ratio (8.76) rectangular microchannel. First, the hydrodynamics of the gas-liquid flows generated at a T-junction was investigated for fifteen solvents commonly used in organic synthesis. The classical literature scaling laws were revised to describe the dependence of bubble and slug lengths, and bubble residence time on the liquid nature by introducing their liquid vapour pressure. Liquid film thickness and liquid residence time were estimated from residence time distribution experiments. Secondly, plasma could be successfully generated in these segmented flows for all the liquids. Due to the plasma dissipation of thermal energy, gas phase temperature increased and induced the lengthening of bubbles and the decrease in bubble residence time. Flow pattern was also impacted by the gas temperature increase. A flow map describing the evolution of flow pattern under plasma conditions was built, enabling prediction of the flow pattern based on liquid boiling point and dielectric constant. These microreactors have demonstrated great potential, and by adapting the synthesis solvent or the operating plasma conditions, they could find promising applications in gas-liquid plasma chemical processes.","PeriodicalId":85,"journal":{"name":"Lab on a Chip","volume":null,"pages":null},"PeriodicalIF":6.1,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141489489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Timely and accurate diagnosis is critical for effective healthcare, yet nearly half the global population lacks access to basic diagnostics. Point-of-care (POC) testing offers partial solutions by enabling low-cost, rapid diagnosis at the patient's location. At-home POC devices have the potential to advance preventive care and early disease detection. Nevertheless, effective sample preparation and detection methods are essential for accurate results. This review surveys recent advances in sample preparation and detection methods at POC. The goal is to provide an in-depth understanding of how these technologies can enhance at-home POC devices. Lateral flow assays, nucleic acid tests, and virus detection methods are at the forefront of POC diagnostic technology, offering rapid and sensitive tools for identifying and measuring pathogens, biomarkers, and viral infections. By illuminating cutting-edge research on assay development for POC diagnostics, this review aims to accelerate progress towards widely available, user-friendly, at-home health monitoring tools that empower individuals in personalized healthcare in the future.
{"title":"Sample preparation and detection methods in point-of-care devices towards future at-home testing.","authors":"George Adedokun, Morteza Alipanah, Z Hugh Fan","doi":"10.1039/d3lc00943b","DOIUrl":"https://doi.org/10.1039/d3lc00943b","url":null,"abstract":"<p><p>Timely and accurate diagnosis is critical for effective healthcare, yet nearly half the global population lacks access to basic diagnostics. Point-of-care (POC) testing offers partial solutions by enabling low-cost, rapid diagnosis at the patient's location. At-home POC devices have the potential to advance preventive care and early disease detection. Nevertheless, effective sample preparation and detection methods are essential for accurate results. This review surveys recent advances in sample preparation and detection methods at POC. The goal is to provide an in-depth understanding of how these technologies can enhance at-home POC devices. Lateral flow assays, nucleic acid tests, and virus detection methods are at the forefront of POC diagnostic technology, offering rapid and sensitive tools for identifying and measuring pathogens, biomarkers, and viral infections. By illuminating cutting-edge research on assay development for POC diagnostics, this review aims to accelerate progress towards widely available, user-friendly, at-home health monitoring tools that empower individuals in personalized healthcare in the future.</p>","PeriodicalId":85,"journal":{"name":"Lab on a Chip","volume":null,"pages":null},"PeriodicalIF":6.1,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141475477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The metastatic cascade includes a blood circulation step for cells detached from the primary tumor. This stage involves significant shear stress as well as large and fast deformations as the cells circulate through the microvasculature. These mechanical stimuli are well reproduced in microfluidic devices. However, the recovery dynamics after deformation is also pivotal to understand how a cell can pass through the multiple capillary constrictions encountered during a single hemodynamic cycle. The microfluidic system developed in this work allows to study single cell recovery in flow-free conditions following pressure-actuated cell deformation inside constricted microchannels. We used three breast cancer cell lines - namely MCF-7, SK-BR3 and MDA-MB231 - as cellular models representative of different cancer phenotypes. Changing the size of the constriction allows to explore moderate to strong deformation regimes, the latter being associated to the formation of plasma membrane blebs. In the regime of moderate deformation, all cell types display a fast elastic recovery behavior followed by a slower viscoelastic regime, well described by a double exponential decay. Among the three cell types, cells of the mesenchymal phenotype, i.e. the MDA-MB231 cells, are softer and the most fluid-like, in agreement with previous studies. Our main finding here is that the fast elastic recovery regime revealed by our novel microfluidic system is under the control of cell contractility ensured by the integrity of the cell cortex. Our results suggest that the cell cortex plays a major role during the transit of circulating tumor cells by allowing their fast morphological recovery after deformation in blood capillaries.
{"title":"Deformation under flow and morphological recovery of cancer cells","authors":"Emile Gasser, Emilie Su, Kotryna Vaidžiulytė, Nassiba Abbade, Hamizah Cognart, Jean-Baptiste Manneville, Jean-Louis Viovy, Matthieu Piel, Jean-Yves Pierga, Kyohei Terao, Catherine Villard","doi":"10.1039/d4lc00246f","DOIUrl":"https://doi.org/10.1039/d4lc00246f","url":null,"abstract":"The metastatic cascade includes a blood circulation step for cells detached from the primary tumor. This stage involves significant shear stress as well as large and fast deformations as the cells circulate through the microvasculature. These mechanical stimuli are well reproduced in microfluidic devices. However, the recovery dynamics after deformation is also pivotal to understand how a cell can pass through the multiple capillary constrictions encountered during a single hemodynamic cycle. The microfluidic system developed in this work allows to study single cell recovery in flow-free conditions following pressure-actuated cell deformation inside constricted microchannels. We used three breast cancer cell lines - namely MCF-7, SK-BR3 and MDA-MB231 - as cellular models representative of different cancer phenotypes. Changing the size of the constriction allows to explore moderate to strong deformation regimes, the latter being associated to the formation of plasma membrane blebs. In the regime of moderate deformation, all cell types display a fast elastic recovery behavior followed by a slower viscoelastic regime, well described by a double exponential decay. Among the three cell types, cells of the mesenchymal phenotype, i.e. the MDA-MB231 cells, are softer and the most fluid-like, in agreement with previous studies. Our main finding here is that the fast elastic recovery regime revealed by our novel microfluidic system is under the control of cell contractility ensured by the integrity of the cell cortex. Our results suggest that the cell cortex plays a major role during the transit of circulating tumor cells by allowing their fast morphological recovery after deformation in blood capillaries.","PeriodicalId":85,"journal":{"name":"Lab on a Chip","volume":null,"pages":null},"PeriodicalIF":6.1,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141475185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tian Fook Kong, Xinhui Shen, Mei Yi Sim, Jin Yong, Tze Kiat Ng, Tsung Wen Chong, Marcos .
We present the development and validation of an impedance-based urine osmometer for accurate and portable measurement of urine osmolality. The urine osmolality of a urine sample can be estimated by determining the concentrations of the conductive solutes and urea which made up of approximately 94% of the urine composition. Our method utilizes impedance measurements to determine the conductive solutes and urea after hydrolysis with urease enzyme. We built an impedance model using sodium chloride (NaCl) and urea at various known concentrations. In this work, we validated the accuracy of the impedance-based urine osmometer by developing a proof-of-concept first prototype and an integrated urine dipstick second prototype, which both prototypes exhibiting an average accuracy of 95.5 ± 2.4% and 89.9 ± 9.1%, respectively in comparison to a clinical freezing point osmometer in the hospital laboratory. While the integrated dipstick design exhibited slightly lower accuracy than the first prototype, it eliminated the need for pre-mixing or manual pipetting. Impedance calibration curves for conductive and non-conductive solutes consistently yielded results for NaCl but underscored challenges in achieving uniform urease enzyme coating on the dipstick. We also investigated the impact of storing urine at room temperature for 24 hours, demonstrating negligible differences in osmolality values. Overall, our impedance-based urine osmometer presents a promising tool for point-of-care urine osmolality measurements, addressing the demand for a portable, accurate, and user-friendly device with potential applications in clinical and home settings.
{"title":"Urine Osmolality Assessment through the Integration of Urea Hydrolysis and Impedance Measurement","authors":"Tian Fook Kong, Xinhui Shen, Mei Yi Sim, Jin Yong, Tze Kiat Ng, Tsung Wen Chong, Marcos .","doi":"10.1039/d4lc00114a","DOIUrl":"https://doi.org/10.1039/d4lc00114a","url":null,"abstract":"We present the development and validation of an impedance-based urine osmometer for accurate and portable measurement of urine osmolality. The urine osmolality of a urine sample can be estimated by determining the concentrations of the conductive solutes and urea which made up of approximately 94% of the urine composition. Our method utilizes impedance measurements to determine the conductive solutes and urea after hydrolysis with urease enzyme. We built an impedance model using sodium chloride (NaCl) and urea at various known concentrations. In this work, we validated the accuracy of the impedance-based urine osmometer by developing a proof-of-concept first prototype and an integrated urine dipstick second prototype, which both prototypes exhibiting an average accuracy of 95.5 ± 2.4% and 89.9 ± 9.1%, respectively in comparison to a clinical freezing point osmometer in the hospital laboratory. While the integrated dipstick design exhibited slightly lower accuracy than the first prototype, it eliminated the need for pre-mixing or manual pipetting. Impedance calibration curves for conductive and non-conductive solutes consistently yielded results for NaCl but underscored challenges in achieving uniform urease enzyme coating on the dipstick. We also investigated the impact of storing urine at room temperature for 24 hours, demonstrating negligible differences in osmolality values. Overall, our impedance-based urine osmometer presents a promising tool for point-of-care urine osmolality measurements, addressing the demand for a portable, accurate, and user-friendly device with potential applications in clinical and home settings.","PeriodicalId":85,"journal":{"name":"Lab on a Chip","volume":null,"pages":null},"PeriodicalIF":6.1,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141475241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Oocyte selection is a crucial step of assisted reproductive treatment. The most common approach relies on the embryologist experience which is inevitably prone to human errors. One potential approach could be using an electrical-based approach as an ameliorative alternative. Here, we developed a simple electrical microsensor to characterize mouse oocytes. The sensor is designed similarly to embryo culture dishes and is familiar to embryologists. Different microelectrode models were simulated for oocyte cells and a more sensitive model was determined. The final microsensor was fabricated. A differential measuring technique was proposed based on the cell presence/absence. We predicted oocyte quality by using three electrical characteristics, oocyte radius, and zona thicknesses, and also these predictions were compared with an embryologist diagnosis. The evaluation of the oocyte membrane capacitance, as an electrophysiological characteristic, was found to be a more reliable method for predicting oocytes with fertilization and blastocyst formation success competence. It achieved 94% and 58% prediction accuracies respectively, surpassing other methods and yielding lower errors. This groundbreaking research represents the first of its kind in this field and we hope that this will be a step towards improving the accuracy of the treatments.
{"title":"Simple Bioelectrical Microsensor: Oocyte Quality Prediction via Membrane Electrophysiological Characterization","authors":"Peyman Palay, Davood Fathi, Hassan Saffari, Fatemeh Hassani, Samira Hajiaghalou, Rouhollah Fathi","doi":"10.1039/d3lc01120h","DOIUrl":"https://doi.org/10.1039/d3lc01120h","url":null,"abstract":"Oocyte selection is a crucial step of assisted reproductive treatment. The most common approach relies on the embryologist experience which is inevitably prone to human errors. One potential approach could be using an electrical-based approach as an ameliorative alternative. Here, we developed a simple electrical microsensor to characterize mouse oocytes. The sensor is designed similarly to embryo culture dishes and is familiar to embryologists. Different microelectrode models were simulated for oocyte cells and a more sensitive model was determined. The final microsensor was fabricated. A differential measuring technique was proposed based on the cell presence/absence. We predicted oocyte quality by using three electrical characteristics, oocyte radius, and zona thicknesses, and also these predictions were compared with an embryologist diagnosis. The evaluation of the oocyte membrane capacitance, as an electrophysiological characteristic, was found to be a more reliable method for predicting oocytes with fertilization and blastocyst formation success competence. It achieved 94% and 58% prediction accuracies respectively, surpassing other methods and yielding lower errors. This groundbreaking research represents the first of its kind in this field and we hope that this will be a step towards improving the accuracy of the treatments.","PeriodicalId":85,"journal":{"name":"Lab on a Chip","volume":null,"pages":null},"PeriodicalIF":6.1,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141463112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Léonard Bezinge, Andrew deMello, Chih-Jen Shih, Daniel Ashley Richards
Paper-based rapid diagnostic tests (RDTs) are an essential component of modern healthcare, particularly for the management of infectious diseases. Despite their utility, these capillary-driven RDTs are compromised by high failure rates, primarily caused by user error. This limits their utility in complex assays that require multiple user operations. Here, we demonstrate how this issue can be directly addressed through continuous electrochemical monitoring of reagent flow inside an RDT using embedded graphenized electrodes. Our method relies on applying short voltage pulses and measuring variations in capacitive discharge currents to precisely determine the flow times of injected samples and reagents. This information is reported to the user, guiding them through the testing process, highlighting failure cases and ultimately decreasing errors. Significantly, the same electrodes can be used to quantify electrochemical signals from immunoassays, providing an integrated solution for both monitoring assays and reporting results. We demonstrate the applicability of this approach in a serology test for the detection of anti-SARS-CoV-2 IgG in clinical serum samples. This method paves the way towards “smart” RDTs able to continuously monitor the testing process and improve the robustness of point-of-care diagnostics.
{"title":"Quantitative reagent monitoring in paper-based electrochemical rapid diagnostic tests","authors":"Léonard Bezinge, Andrew deMello, Chih-Jen Shih, Daniel Ashley Richards","doi":"10.1039/d4lc00390j","DOIUrl":"https://doi.org/10.1039/d4lc00390j","url":null,"abstract":"Paper-based rapid diagnostic tests (RDTs) are an essential component of modern healthcare, particularly for the management of infectious diseases. Despite their utility, these capillary-driven RDTs are compromised by high failure rates, primarily caused by user error. This limits their utility in complex assays that require multiple user operations. Here, we demonstrate how this issue can be directly addressed through continuous electrochemical monitoring of reagent flow inside an RDT using embedded graphenized electrodes. Our method relies on applying short voltage pulses and measuring variations in capacitive discharge currents to precisely determine the flow times of injected samples and reagents. This information is reported to the user, guiding them through the testing process, highlighting failure cases and ultimately decreasing errors. Significantly, the same electrodes can be used to quantify electrochemical signals from immunoassays, providing an integrated solution for both monitoring assays and reporting results. We demonstrate the applicability of this approach in a serology test for the detection of anti-SARS-CoV-2 IgG in clinical serum samples. This method paves the way towards “smart” RDTs able to continuously monitor the testing process and improve the robustness of point-of-care diagnostics.","PeriodicalId":85,"journal":{"name":"Lab on a Chip","volume":null,"pages":null},"PeriodicalIF":6.1,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141462423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Precise manipulation of individual DNA molecules entering and leaving the channel ports, as well as their smooth passage across the channel, is essential for the detection and screening of DNA molecules using nano-/micro-fluidic technologies. In this paper, by combining single-molecule fluorescence imaging and numerical simulations, the motion states of DNA molecules translocating through a microfluidic channel under the action of the applied electric field are monitored and analyzed in detail. It is found that, under certain conditions of the applied electric field DNA molecules exhibit various motion states, including translation crossing, deflection outflow, reverse outflow, reciprocal movement, and elliptical movement. Simulations indicate that, under the action of Saffman force, DNA molecules can only undergo deflective motion when they experience a velocity gradient in the microchannel flow field; and they can only undergo elliptical motion when their deflective motion is accompanied by a spin motion. In this case, the Magnus force also plays an important role. The detailed study and elucidation of the movement states, dynamic characteristics and mechanisms of DNA molecules such as the deflective and elliptical motions under the actions of Saffman and Magnus forces have helpful implications for the development of related DNA/gene nano-/microfluidic chips, and for the separation, screening and detection of DNA molecules.
要利用纳米/微流体技术检测和筛选 DNA 分子，就必须精确控制单个 DNA 分子进出通道口并使其顺利通过通道。本文结合单分子荧光成像和数值模拟，详细监测和分析了 DNA 分子在外加电场作用下通过微流控通道的运动状态。研究发现，在一定的外加电场条件下，DNA 分子呈现出多种运动状态，包括平移穿越、偏转流出、反向流出、往复运动和椭圆运动。模拟结果表明，在萨夫曼力的作用下，DNA 分子只有在微通道流场中经历速度梯度时才能发生偏转运动；只有在偏转运动伴随自旋运动时，DNA 分子才能发生椭圆运动。在这种情况下，马格努斯力也发挥了重要作用。详细研究和阐明DNA分子在萨夫曼力和马格努斯力作用下的偏转运动和椭圆运动等运动状态、动态特征和机理，对开发相关的DNA/基因纳米/微流控芯片，以及对DNA分子的分离、筛选和检测都有帮助。
{"title":"Dynamic Behavior of DNA Molecules in Microchannels: Exploring Deflective, Elliptical, and Spin Motions Induced by Saffman and Magnus Forces","authors":"Zhiwei Li, Qiong Wang, Yong Niu, Ruiyu Wang, Wei Zhao, Chen Zhang, Guiren Wang, Kaige Wang","doi":"10.1039/d4lc00140k","DOIUrl":"https://doi.org/10.1039/d4lc00140k","url":null,"abstract":"Precise manipulation of individual DNA molecules entering and leaving the channel ports, as well as their smooth passage across the channel, is essential for the detection and screening of DNA molecules using nano-/micro-fluidic technologies. In this paper, by combining single-molecule fluorescence imaging and numerical simulations, the motion states of DNA molecules translocating through a microfluidic channel under the action of the applied electric field are monitored and analyzed in detail. It is found that, under certain conditions of the applied electric field DNA molecules exhibit various motion states, including translation crossing, deflection outflow, reverse outflow, reciprocal movement, and elliptical movement. Simulations indicate that, under the action of Saffman force, DNA molecules can only undergo deflective motion when they experience a velocity gradient in the microchannel flow field; and they can only undergo elliptical motion when their deflective motion is accompanied by a spin motion. In this case, the Magnus force also plays an important role. The detailed study and elucidation of the movement states, dynamic characteristics and mechanisms of DNA molecules such as the deflective and elliptical motions under the actions of Saffman and Magnus forces have helpful implications for the development of related DNA/gene nano-/microfluidic chips, and for the separation, screening and detection of DNA molecules.","PeriodicalId":85,"journal":{"name":"Lab on a Chip","volume":null,"pages":null},"PeriodicalIF":6.1,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141462590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zeming Yang, Junxiao Zhang, Jincheng Zhao, Wen Zhou, Yuanyue Cheng, Zhantang Xu, Panpan Wei, Zihui Wang, Haorui Liang, Cai Li
Optical detection is an indispensable part of microfluidic systems for nutrient determination in seawater. Coupling total internal reflection capillaries with microfluidic chips is a practical alternative to increase the optical path length for high-sensitivity and a low detection limit in colorimetric assays, which has not been applied in microfluidic devices for seawater nutrients. Here, we present an online microfluidic system which integrated a total internal reflection capillary made of Teflon AF 2400 for the high-sensitivity detection of nitrite and nitrate in seawater. The off-chip capillary lengthens the optical path without changing the internal flow path of the microfluidic chip, enhancing the sensitivity, reducing the detection limit and widening the dynamic range of the system, which significantly improves the performance of the microfluidic system based on wet-chemistry. The detection limit for nitrite is 0.0150 μM using an external 20 cm capillary and 0.0936 μM using an internal 5 cm absorption cell, providing an over 6-fold improvement. Laboratory analysis of surface seawater samples collected from the South China Sea with this system and a one-month online deployment of an autonomous analyzer developed based on this system at a station revealed correlations between the nitrite and nitrate with tide, salinity and chlorophyll over slight variations and narrow ranges, demonstrating the high-sensitivity of this method.
{"title":"A high-sensitivity lab-on-a-chip analyzer for online monitoring of nitrite and nitrate in seawater based on liquid waveguide capillary cells","authors":"Zeming Yang, Junxiao Zhang, Jincheng Zhao, Wen Zhou, Yuanyue Cheng, Zhantang Xu, Panpan Wei, Zihui Wang, Haorui Liang, Cai Li","doi":"10.1039/d4lc00248b","DOIUrl":"https://doi.org/10.1039/d4lc00248b","url":null,"abstract":"Optical detection is an indispensable part of microfluidic systems for nutrient determination in seawater. Coupling total internal reflection capillaries with microfluidic chips is a practical alternative to increase the optical path length for high-sensitivity and a low detection limit in colorimetric assays, which has not been applied in microfluidic devices for seawater nutrients. Here, we present an online microfluidic system which integrated a total internal reflection capillary made of Teflon AF 2400 for the high-sensitivity detection of nitrite and nitrate in seawater. The off-chip capillary lengthens the optical path without changing the internal flow path of the microfluidic chip, enhancing the sensitivity, reducing the detection limit and widening the dynamic range of the system, which significantly improves the performance of the microfluidic system based on wet-chemistry. The detection limit for nitrite is 0.0150 μM using an external 20 cm capillary and 0.0936 μM using an internal 5 cm absorption cell, providing an over 6-fold improvement. Laboratory analysis of surface seawater samples collected from the South China Sea with this system and a one-month online deployment of an autonomous analyzer developed based on this system at a station revealed correlations between the nitrite and nitrate with tide, salinity and chlorophyll over slight variations and narrow ranges, demonstrating the high-sensitivity of this method.","PeriodicalId":85,"journal":{"name":"Lab on a Chip","volume":null,"pages":null},"PeriodicalIF":6.1,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141462425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nanoparticles-mediated photoporation has arisen as universal intracellular delivery tool; however, the direct interaction of nanoparticles and cells hampers its clinical translation. Here, we report a uniform contactless intracellular delivery that transfect large number of cells within a minute and avoids the direct contact of nanoparticles and cells, thereby improving the cell viability. Our platform consists of an array of polydimethylsiloxane (PDMS) mixed reduced graphene oxide nanoflakes (rGO) pyramidal microtips, which uniformly distributed at the apex of the tip. The extraordinary optoelectronic properties of rGO were combined with the micro-pyramidal cavity to entrap light in micro-cavity and efficiently convert into heat through multiple reflections and absorptions. As a result, an ultralow infra-red laser pulse irradiation, could create cavitation bubbles followed by cell membrane deformation and biomolecular delivery. Using this delivery platform, we have achieved the delivery of small to large cargo (668 Da to 465 kDa) in various mammalian cells, including hard-to-transfect H9C2 cardiomyocytes. The best results were achieved for enzyme (465 kDa) delivery with a transfection efficiency and cell viability of 95% and 98%, respectively, in SiHa cells. The highly efficient cargo delivery tool demonstrated a safe and effective approach for cell therapy and diagnostics.
{"title":"Ultra-Low Intensity Light Pulses for Large Cargo Delivery into Hard-to-Transfect Cells using rGO Mixed PDMS Microtip Device","authors":"Hima Harshan Padma, Kavitha Illath, Donia Dominic, Hwan-You Chang, Moeto Nagai, Rajdeep Ojha, Srabani Kar, Tuhin Subhra Santra","doi":"10.1039/d4lc00121d","DOIUrl":"https://doi.org/10.1039/d4lc00121d","url":null,"abstract":"Nanoparticles-mediated photoporation has arisen as universal intracellular delivery tool; however, the direct interaction of nanoparticles and cells hampers its clinical translation. Here, we report a uniform contactless intracellular delivery that transfect large number of cells within a minute and avoids the direct contact of nanoparticles and cells, thereby improving the cell viability. Our platform consists of an array of polydimethylsiloxane (PDMS) mixed reduced graphene oxide nanoflakes (rGO) pyramidal microtips, which uniformly distributed at the apex of the tip. The extraordinary optoelectronic properties of rGO were combined with the micro-pyramidal cavity to entrap light in micro-cavity and efficiently convert into heat through multiple reflections and absorptions. As a result, an ultralow infra-red laser pulse irradiation, could create cavitation bubbles followed by cell membrane deformation and biomolecular delivery. Using this delivery platform, we have achieved the delivery of small to large cargo (668 Da to 465 kDa) in various mammalian cells, including hard-to-transfect H9C2 cardiomyocytes. The best results were achieved for enzyme (465 kDa) delivery with a transfection efficiency and cell viability of 95% and 98%, respectively, in SiHa cells. The highly efficient cargo delivery tool demonstrated a safe and effective approach for cell therapy and diagnostics.","PeriodicalId":85,"journal":{"name":"Lab on a Chip","volume":null,"pages":null},"PeriodicalIF":6.1,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141462576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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