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Dr. P. Ravi Selvaganapathy
Department of Mechanical Engineering and School of Biomedical Engineering, McMaster University, Hamilton, ON L8S 4L7, Canada

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0 Microfluidics
0 smart textiles
0 bioprinting
0 Micro/nanofabrication
0 Microelectromechanical systems

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Microfluidics
bioprinting
Artificial Organs

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Journal article
Published: 31 July 2021 in Materials & Design
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In recent years, there has been an increasing interest in methods to fabricate hydrophobic surfaces. Hydrophobic surfaces have been used in multiple applications in microfluidic devices to control fluid flow, as self-cleaning surfaces and also in de-icing or for drag reduction. Conventionally, hydrophobic surfaces were created by laser processing, self-assembly and other chemical processing methods. However, in many of these methods, hydrophobicity of the surface cannot be maintained for an extended time or restricted to limited set of materials. In some applications, creation of anisotropy in the hydrophobic property and the ability to pattern it, is important. Here, a low-cost, high-throughput method to generate highly hydrophobic and anisotropic surface has been developed. This method uses Computer Numerical Control machining employing diamond tools whose tips have been micro-structured using Focused Ion Beam that enables parallelization and achieves at least four times higher machining speed compared with other methods. The versatility of this method has been demonstrated by machining both metal and polymeric materials. Significant anisotropic wetting has been observed on the machined surface with the anisotropy in directional contact angle of up to 71.6°. Highly-hydrophobic surfaces with contact angle of 163.1° on 6061 Aluminum Alloy and 155.7° on polymethyl methacrylate surface were created.

ACS Style

Rong Wu; M. Tauhiduzzaman; P. Ravi Selvaganapathy. Anisotropic wetting surfaces machined by diamond tool with tips microstructured by focused ion beam. Materials & Design 2021, 210, 110014 .

AMA Style

Rong Wu, M. Tauhiduzzaman, P. Ravi Selvaganapathy. Anisotropic wetting surfaces machined by diamond tool with tips microstructured by focused ion beam. Materials & Design. 2021; 210 ():110014.

Chicago/Turabian Style

Rong Wu; M. Tauhiduzzaman; P. Ravi Selvaganapathy. 2021. "Anisotropic wetting surfaces machined by diamond tool with tips microstructured by focused ion beam." Materials & Design 210, no. : 110014.

Journal article
Published: 08 June 2021 in Additive Manufacturing
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Additive manufacturing and 3D printing technology using thermoplastics and metals have found mainstream use and acceptance. Nevertheless, these methods are not suitable for several industrially important materials, such as silicones and epoxies that are formed by mixing two or more reactive components and chemically inducing crosslinking. The reaction increases the viscosity of the material significantly, which greatly affects the printing process. Here, we develop an inkjet-based printing method that generates droplets of the reactive components simultaneously, merges and mixes them in free space and deposits these curing droplets so that 3D structures can be formed. It uses low viscosity, highly reactive silicone inks that cannot be printed using conventional methods of additive manufacturing and expands the range of 3D printable materials. The method enables stable and uninterrupted printing and allows for multi and rapid start-stop cycles. The high reactivity of the ink used allows printing of high aspect ratio features, as well as structures that do not require supporting scaffolds. The capabilities of the new printing method, such as non-contact printing, on-demand printing, and the ability to handle highly reactive materials make it suitable for a wide range of industrial and home use of 3D printing technology for non-thermoplastic polymeric materials.

ACS Style

Monika Śliwiak; Robert Bui; Michael A. Brook; P. Ravi Selvaganapathy. 3D printing of highly reactive silicones using inkjet type droplet ejection and free space droplet merging and reaction. Additive Manufacturing 2021, 46, 102099 .

AMA Style

Monika Śliwiak, Robert Bui, Michael A. Brook, P. Ravi Selvaganapathy. 3D printing of highly reactive silicones using inkjet type droplet ejection and free space droplet merging and reaction. Additive Manufacturing. 2021; 46 ():102099.

Chicago/Turabian Style

Monika Śliwiak; Robert Bui; Michael A. Brook; P. Ravi Selvaganapathy. 2021. "3D printing of highly reactive silicones using inkjet type droplet ejection and free space droplet merging and reaction." Additive Manufacturing 46, no. : 102099.

Response
Published: 04 May 2021 in Advanced Science
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ACS Style

Niels Rochow; Christoph Fusch; Ponnambalam Ravi Selvaganapathy. Reply to the “Comment on ‘A Pumpless Microfluidic Neonatal Lung Assist Device for Support of Preterm Neonates in Respiratory Distress’” by Li Wang, Fang Li, Zhichun Feng, Yuan Shi. Advanced Science 2021, 8, 2100831 .

AMA Style

Niels Rochow, Christoph Fusch, Ponnambalam Ravi Selvaganapathy. Reply to the “Comment on ‘A Pumpless Microfluidic Neonatal Lung Assist Device for Support of Preterm Neonates in Respiratory Distress’” by Li Wang, Fang Li, Zhichun Feng, Yuan Shi. Advanced Science. 2021; 8 (12):2100831.

Chicago/Turabian Style

Niels Rochow; Christoph Fusch; Ponnambalam Ravi Selvaganapathy. 2021. "Reply to the “Comment on ‘A Pumpless Microfluidic Neonatal Lung Assist Device for Support of Preterm Neonates in Respiratory Distress’” by Li Wang, Fang Li, Zhichun Feng, Yuan Shi." Advanced Science 8, no. 12: 2100831.

Journal article
Published: 26 January 2021 in Micromachines
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Polydimethylsiloxane (PDMS) is a silicone-based synthetic material used in various biomedical applications due to its properties, including transparency, flexibility, permeability to gases, and ease of use. Though PDMS facilitates and assists the fabrication of complicated geometries at micro- and nano-scales, it does not optimally interact with cells for adherence and proliferation. Various strategies have been proposed to render PDMS to enhance cell attachment. The majority of these surface modification techniques have been offered for a static cell culture system. However, dynamic cell culture systems such as organ-on-a-chip devices are demanding platforms that recapitulate a living tissue microenvironment’s complexity. In organ-on-a-chip platforms, PDMS surfaces are usually coated by extracellular matrix (ECM) proteins, which occur as a result of a physical and weak bonding between PDMS and ECM proteins, and this binding can be degraded when it is exposed to shear stresses. This work reports static and dynamic coating methods to covalently bind collagen within a PDMS-based microfluidic device using polydopamine (PDA). These coating methods were evaluated using water contact angle measurement and atomic force microscopy (AFM) to optimize coating conditions. The biocompatibility of collagen-coated PDMS devices was assessed by culturing primary human bronchial epithelial cells (HBECs) in microfluidic devices. It was shown that both PDA coating methods could be used to bind collagen, thereby improving cell adhesion (approximately three times higher) without showing any discernible difference in cell attachment between these two methods. These results suggested that such a surface modification can help coat extracellular matrix protein onto PDMS-based microfluidic devices.

ACS Style

Mohammadhossein Dabaghi; Shadi Shahriari; Neda Saraei; Kevin Da; Abiram Chandiramohan; Ponnambalam Selvaganapathy; Jeremy Hirota. Surface Modification of PDMS-Based Microfluidic Devices with Collagen Using Polydopamine as a Spacer to Enhance Primary Human Bronchial Epithelial Cell Adhesion. Micromachines 2021, 12, 132 .

AMA Style

Mohammadhossein Dabaghi, Shadi Shahriari, Neda Saraei, Kevin Da, Abiram Chandiramohan, Ponnambalam Selvaganapathy, Jeremy Hirota. Surface Modification of PDMS-Based Microfluidic Devices with Collagen Using Polydopamine as a Spacer to Enhance Primary Human Bronchial Epithelial Cell Adhesion. Micromachines. 2021; 12 (2):132.

Chicago/Turabian Style

Mohammadhossein Dabaghi; Shadi Shahriari; Neda Saraei; Kevin Da; Abiram Chandiramohan; Ponnambalam Selvaganapathy; Jeremy Hirota. 2021. "Surface Modification of PDMS-Based Microfluidic Devices with Collagen Using Polydopamine as a Spacer to Enhance Primary Human Bronchial Epithelial Cell Adhesion." Micromachines 12, no. 2: 132.

Methods article
Published: 13 January 2021 in Cells Tissues Organs
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Global meat consumption has been growing on a per capita basis over the past 20 years resulting in ever-increasing devotion of resources in the form of arable land and potable water to animal husbandry which is unsustainable and inefficient. One approach to meet this insatiable demand is to use biofabrication methods used in tissue engineering in order to make skeletal muscle tissue-like constructs known as cultivated meat to be used as a food source. Here, we demonstrate the use of a scaffold-free biofabrication method that forms cell sheets composed of murine adipocytes and skeletal muscle cells and assembles these sheets in parallel to create a 3D meat-like construct without the use of any exogenous materials. This layer-by-layer self-assembly and stacking process is fast (4 days of culture to form sheets and few hours for assembly) and scalable (stable sheets with diameters >3 cm are formed). Tissues formed with only muscle cells were equivalent to lean meat with comparable protein and fat contents (lean beef had 1.5 and 0.9 times protein and fat, respectively, as our constructs) and incorporating adipocyte cells in different ratios to myoblasts and/or treatment with different media cocktails resulted in a 5% (low fat meat) to 35% (high fat meat) increase in the fat content. Not only such constructs can be used as cultivated meat, they can also be used as skeletal muscle models.

ACS Style

Alireza Shahin-Shamsabadi; P. Ravi Selvaganapathy. Engineering Murine Adipocytes and Skeletal Muscle Cells in Meat-like Constructs Using Self-Assembled Layer-by-Layer Biofabrication: A Platform for Development of Cultivated Meat. Cells Tissues Organs 2021, 1 -9.

AMA Style

Alireza Shahin-Shamsabadi, P. Ravi Selvaganapathy. Engineering Murine Adipocytes and Skeletal Muscle Cells in Meat-like Constructs Using Self-Assembled Layer-by-Layer Biofabrication: A Platform for Development of Cultivated Meat. Cells Tissues Organs. 2021; ():1-9.

Chicago/Turabian Style

Alireza Shahin-Shamsabadi; P. Ravi Selvaganapathy. 2021. "Engineering Murine Adipocytes and Skeletal Muscle Cells in Meat-like Constructs Using Self-Assembled Layer-by-Layer Biofabrication: A Platform for Development of Cultivated Meat." Cells Tissues Organs , no. : 1-9.

Review
Published: 25 December 2020 in Biosensors
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Hydrogen peroxide (H2O2) is a key molecule in numerous physiological, industrial, and environmental processes. H2O2 is monitored using various methods like colorimetry, luminescence, fluorescence, and electrochemical methods. Here, we aim to provide a comprehensive review of solid state sensors to monitor H2O2. The review covers three categories of sensors: chemiresistive, conductometric, and field effect transistors. A brief description of the sensing mechanisms of these sensors has been provided. All three sensor types are evaluated based on the sensing parameters like sensitivity, limit of detection, measuring range and response time. We highlight those sensors which have advanced the field by using innovative materials or sensor fabrication techniques. Finally, we discuss the limitations of current solid state sensors and the future directions for research and development in this exciting area.

ACS Style

Vinay Patel; Peter Kruse; Ponnambalam Selvaganapathy. Solid State Sensors for Hydrogen Peroxide Detection. Biosensors 2020, 11, 9 .

AMA Style

Vinay Patel, Peter Kruse, Ponnambalam Selvaganapathy. Solid State Sensors for Hydrogen Peroxide Detection. Biosensors. 2020; 11 (1):9.

Chicago/Turabian Style

Vinay Patel; Peter Kruse; Ponnambalam Selvaganapathy. 2020. "Solid State Sensors for Hydrogen Peroxide Detection." Biosensors 11, no. 1: 9.

Journal article
Published: 04 December 2020 in Sensors and Actuators B: Chemical
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Bedside diagnostics using protein biomarkers requires rapid concentration, isolation and measurement of these specific biomarkers from a complex matrix in a low cost and portable manner. Traditional separation using gel electrophoresis separates the sample into all its constituent elements and requires high voltages and/or long runtime which is often unnecessary for diagnostics where only a specific biomarker needs to be quantified. Digital isoelectric trapping can be used to isolate and concentrate proteins but requires UV cured immobiline gels that have defined pH values and are not tunable to target specific proteins. Here, we have developed miniaturized isoelectric gates to separate, concentrate and quantify a targeted biomarker based on its isoelectric point, from a complex matrix in under 20 min. We designed specific isoelectric gates to concentrate and quantify bovine serum albumin (BSA) at a concentration of 1−5 mg/mL with a peak concentration of over 300 mg/mL, while maintaining its solubility. Next, we have demonstrated isolation of human protein C from a mixture with 1000-fold higher concentration of BSA with no additional processing. Finally, we have demonstrated rapid (< 20 min) separation, concentration and quantification of ovomucoid in a fresh hen egg using dual isoelectric gates at pH 3.9 and 4.3 to trap ovomucoid with an isoelectric point of 4.1 using a low applied voltage of only 15 V. By using low cost agarose gels instead of expensive immobilines, this device reduced the cost and complexity of separation. The combination of low-cost, tunability, fast-runtime, low-operating voltage makes this technique attractive for use in point-of-care biomarker detection without specific antibody tags.

ACS Style

Sreekant Damodara; Dhruva J. Dwivedi; Patricia C. Liaw; Alison E. Fox-Robichaud; P. Ravi Selvaganapathy. Single step separation and concentration of biomarker proteins using agarose based miniaturized isoelectric gates for point of care diagnostics. Sensors and Actuators B: Chemical 2020, 330, 129265 .

AMA Style

Sreekant Damodara, Dhruva J. Dwivedi, Patricia C. Liaw, Alison E. Fox-Robichaud, P. Ravi Selvaganapathy. Single step separation and concentration of biomarker proteins using agarose based miniaturized isoelectric gates for point of care diagnostics. Sensors and Actuators B: Chemical. 2020; 330 ():129265.

Chicago/Turabian Style

Sreekant Damodara; Dhruva J. Dwivedi; Patricia C. Liaw; Alison E. Fox-Robichaud; P. Ravi Selvaganapathy. 2020. "Single step separation and concentration of biomarker proteins using agarose based miniaturized isoelectric gates for point of care diagnostics." Sensors and Actuators B: Chemical 330, no. : 129265.

Journal article
Published: 06 November 2020 in ACS Applied Nano Materials
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ACS Style

Dipankar Saha; Ponnambalam Ravi Selvaganapathy; Peter Kruse. Peroxide-Induced Tuning of the Conductivity of Nanometer-Thick MoS2 Films for Solid-State Sensors. ACS Applied Nano Materials 2020, 1 .

AMA Style

Dipankar Saha, Ponnambalam Ravi Selvaganapathy, Peter Kruse. Peroxide-Induced Tuning of the Conductivity of Nanometer-Thick MoS2 Films for Solid-State Sensors. ACS Applied Nano Materials. 2020; ():1.

Chicago/Turabian Style

Dipankar Saha; Ponnambalam Ravi Selvaganapathy; Peter Kruse. 2020. "Peroxide-Induced Tuning of the Conductivity of Nanometer-Thick MoS2 Films for Solid-State Sensors." ACS Applied Nano Materials , no. : 1.

Paper
Published: 26 October 2020 in Nanoscale Advances
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Multi-step miniaturization to sub-micron dimensions using shrinkable polymer films.

ACS Style

Shady Sayed; P. Ravi Selvaganapathy. Multi-step proportional miniaturization to sub-micron dimensions using pre-stressed polymer films. Nanoscale Advances 2020, 2, 5461 -5467.

AMA Style

Shady Sayed, P. Ravi Selvaganapathy. Multi-step proportional miniaturization to sub-micron dimensions using pre-stressed polymer films. Nanoscale Advances. 2020; 2 (11):5461-5467.

Chicago/Turabian Style

Shady Sayed; P. Ravi Selvaganapathy. 2020. "Multi-step proportional miniaturization to sub-micron dimensions using pre-stressed polymer films." Nanoscale Advances 2, no. 11: 5461-5467.

Journal article
Published: 11 October 2020 in Sensors and Actuators B: Chemical
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Silver is used as a water disinfectant in hospital settings as well as in purifiers for potable water. Although there are no strict regulations on the concentration of silver in water, adverse effects such as argyria and respiratory tract irritation have been correlated to excess silver consumption. Based on this, the levels of silver in water are recommended to be maintained below 100 ppb to ensure safety for human consumption. In this work, we present a silver sensor for use in aqueous media that utilizes bathocuproine, a silver selective chromophore, adsorbed onto few-layer graphene (FLG) flake networks for the chemiresistive detection of silver. Complexation of silver to bathocuproine modulates the conductivity of the FLG film, which can be probed by applying a small voltage bias. The decrease in resistance of the film correlates with the concentration of silver in solution between 3 ppb and 1 ppm. Exposing the sensor to a lower pH resets the sensor, allowing it to be reused and reset multiple times. This sensor demonstrates a new pathway to chemiresistive cation sensing using known selective complexing agents adsorbed onto graphitic thin films. This concept can be expanded to the detection of other relevant analytes in domestic, industrial and environmental water sources.

ACS Style

Johnson Dalmieda; Ana Zubiarrain-Laserna; Devanjith Ganepola; P. Ravi Selvaganapathy; Peter Kruse. Chemiresistive detection of silver ions in aqueous media. Sensors and Actuators B: Chemical 2020, 328, 129023 .

AMA Style

Johnson Dalmieda, Ana Zubiarrain-Laserna, Devanjith Ganepola, P. Ravi Selvaganapathy, Peter Kruse. Chemiresistive detection of silver ions in aqueous media. Sensors and Actuators B: Chemical. 2020; 328 ():129023.

Chicago/Turabian Style

Johnson Dalmieda; Ana Zubiarrain-Laserna; Devanjith Ganepola; P. Ravi Selvaganapathy; Peter Kruse. 2020. "Chemiresistive detection of silver ions in aqueous media." Sensors and Actuators B: Chemical 328, no. : 129023.

Full paper
Published: 29 September 2020 in Advanced Science
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Premature neonates suffer from respiratory morbidity as their lungs are immature, and current supportive treatment such as mechanical ventilation or extracorporeal membrane oxygenation causes iatrogenic injuries. A non‐invasive and biomimetic concept known as the “artificial placenta” (AP) would be beneficial to overcome complications associated with the current respiratory support of preterm infants. Here, a pumpless oxygenator connected to the systemic circulation supports the lung function to relieve respiratory distress. In this paper, the first successful operation of a microfluidic, artificial placenta type neonatal lung assist device (LAD) on a newborn piglet model, which is the closest representation of preterm human infants, is demonstrated. This LAD has high oxygenation capability in both pure oxygen and room air as the sweep gas. The respiratory distress that the newborn piglet is put under during experimentation, repeatedly and over a significant duration of time, is able to be relieved. These findings indicate that this LAD has a potential application as a biomimetic artificial placenta to support the respiratory needs of preterm neonates.

ACS Style

Mohammadhossein Dabaghi; Niels Rochow; Neda Saraei; Gerhard Fusch; Shelley Monkman; Kevin Da; Alireza Shahin‐Shamsabadi; John L. Brash; Dragos Predescu; Kathleen Delaney; Christoph Fusch; P. Ravi Selvaganapathy. A Pumpless Microfluidic Neonatal Lung Assist Device for Support of Preterm Neonates in Respiratory Distress. Advanced Science 2020, 7, 2001860 .

AMA Style

Mohammadhossein Dabaghi, Niels Rochow, Neda Saraei, Gerhard Fusch, Shelley Monkman, Kevin Da, Alireza Shahin‐Shamsabadi, John L. Brash, Dragos Predescu, Kathleen Delaney, Christoph Fusch, P. Ravi Selvaganapathy. A Pumpless Microfluidic Neonatal Lung Assist Device for Support of Preterm Neonates in Respiratory Distress. Advanced Science. 2020; 7 (21):2001860.

Chicago/Turabian Style

Mohammadhossein Dabaghi; Niels Rochow; Neda Saraei; Gerhard Fusch; Shelley Monkman; Kevin Da; Alireza Shahin‐Shamsabadi; John L. Brash; Dragos Predescu; Kathleen Delaney; Christoph Fusch; P. Ravi Selvaganapathy. 2020. "A Pumpless Microfluidic Neonatal Lung Assist Device for Support of Preterm Neonates in Respiratory Distress." Advanced Science 7, no. 21: 2001860.

Journal article
Published: 01 June 2020 in Materials Today Bio
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Three-dimensional (3D) in vitro tissue models are superior to two-dimensional (2D) cell cultures in replicating natural physiological/pathological conditions by recreating the cellular and cell-matrix interactions more faithfully. Nevertheless, current 3D models lack either the rich multicellular environment or fail to provide appropriate biophysical stimuli both of which are required to properly recapitulate the dynamic in vivo microenvironment of tissues and organs. Here, we describe the rapid construction of multicellular, tubular tissue constructs termed Tissue-in-a-Tube using self-assembly process in tubular molds with the ability to incorporate a variety of biophysical stimuli such as electrical field, mechanical deformation, and shear force of the fluid flow. Unlike other approaches, this method is simple, requires only oxygen permeable silicone tubing that molds the tissue construct and thin stainless-steel pins inserted in it to anchor the construct and could be used to provide electrical and mechanical stimuli, simultaneously. The annular region between the tissue construct and the tubing is used for perfusion. Highly stable, macroscale, and robust constructs anchored to the pins form as a result of self-assembly of the extracellular matrix (ECM) and cells in the bioink that is filled into the tubing. We demonstrate patterning of grafts containing cell types in the constructs in axial and radial modes with clear interface and continuity between the layers. Different environmental factors affecting cell behavior such as compactness of the structure and size of the constructs can be controlled through parameters such as initial cell density, ECM content, tubing size, as well as the distance between anchor pins. Using connectors, network of tubing can be assembled to create complex macrostructured tissues (centimeters length) such as fibers that are bifurcated or columns with different axial thicknesses which can then be used as building blocks for biomimetic constructs or tissue regeneration. The method is versatile and compatible with various cell types including endothelial, epithelial, skeletal muscle cells, osteoblast cells, and neuronal cells. As an example, long mature skeletal muscle and neuronal fibers as well as bone constructs were fabricated with cellular alignment dictated by the applied electrical field. The versatility, speed, and low cost of this method is suited for widespread application in tissue engineering and regenerative medicine.

ACS Style

A. Shahin-Shamsabadi; P.R. Selvaganapathy. Tissue-in-a-Tube: three-dimensional in vitro tissue constructs with integrated multimodal environmental stimulation. Materials Today Bio 2020, 7, 100070 .

AMA Style

A. Shahin-Shamsabadi, P.R. Selvaganapathy. Tissue-in-a-Tube: three-dimensional in vitro tissue constructs with integrated multimodal environmental stimulation. Materials Today Bio. 2020; 7 ():100070.

Chicago/Turabian Style

A. Shahin-Shamsabadi; P.R. Selvaganapathy. 2020. "Tissue-in-a-Tube: three-dimensional in vitro tissue constructs with integrated multimodal environmental stimulation." Materials Today Bio 7, no. : 100070.

Review
Published: 19 May 2020 in Advanced Materials Technologies
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Artificial lungs support patients undergoing open‐heart surgery, organ transplantation, and in serious lung injury by providing oxygenation support through an extracorporeal circuit. Some patients require partial support for durations of a few weeks or months even after the surgery. Therefore, a portable or wearable lung assist device which can be operated for several weeks with minimum maintenance would be ideal. Miniaturization of blood oxygenators, using microfluidic technology, is a promising avenue for the realization of such portable artificial lungs. The microfluidic blood oxygenators (MBOs) are also suitable for neonates with respiratory failure due to their low priming volume and pressure drop. Herein, the history of microfluidic oxygenator development and recent progress in miniaturized artificial lungs are discussed. The MBOs have made significant advances in 1) reducing device size, 2) providing biomimetic blood flow paths, 3) enabling operation in room air, and 4) operating without the need of an external pump. Recent work has demonstrated throughput of up to 150 mL min‐1 of blood and oxygen transfer rate of 60 mL O2 per L of blood. The challenges faced by this technology in practical applications as well as future improvements to meet the requirements for older neonates and even adults are also presented.

ACS Style

Mohammadhossein Dabaghi; Niels Rochow; Neda Saraei; Rupesh Kumar Mahendran; Gerhard Fusch; Anthony K. C. Chan; John L. Brash; Christoph Fusch; Ponnambalam Ravi Selvaganapathy. Miniaturization of Artificial Lungs toward Portability. Advanced Materials Technologies 2020, 5, 1 .

AMA Style

Mohammadhossein Dabaghi, Niels Rochow, Neda Saraei, Rupesh Kumar Mahendran, Gerhard Fusch, Anthony K. C. Chan, John L. Brash, Christoph Fusch, Ponnambalam Ravi Selvaganapathy. Miniaturization of Artificial Lungs toward Portability. Advanced Materials Technologies. 2020; 5 (7):1.

Chicago/Turabian Style

Mohammadhossein Dabaghi; Niels Rochow; Neda Saraei; Rupesh Kumar Mahendran; Gerhard Fusch; Anthony K. C. Chan; John L. Brash; Christoph Fusch; Ponnambalam Ravi Selvaganapathy. 2020. "Miniaturization of Artificial Lungs toward Portability." Advanced Materials Technologies 5, no. 7: 1.

Full paper
Published: 10 May 2020 in Advanced Biosystems
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The molecular mechanisms of the development and progression of diabetes and obesity involve complex interactions between adipocytes and skeletal muscle cells. Although 2D in‐vitro models are the gold standard for the mechanistic study of such behaviors, they do not recreate the complexity and dynamics of the interactions between the cell types involved. Alternatively, animal models are used but are expensive, difficult to visualize or analyze, are not completely representative of human physiology or genetic background, and have associated ethical considerations. 3D co‐culture systems can be complementary to these approaches. Here, using a newly developed 3D biofabrication method, adipocytes and myoblasts are positioned precisely either in direct physical contact or in close proximity such that the paracrine effects could be systematically studied. Suitable protocols for growth and differentiation of both cells in the co‐culture system is also developed. Cells show more restrained lipid and protein production in 3D systems compared to 2D ones and adipocytes show more lipolysis in indirect contact with myoblasts as response to drug treatment. These findings emphasize importance of physical contact between cells that have been overlooked in co‐culture systems using transwell inserts and can be used in studies for the development of anti‐obesity drugs.

ACS Style

Alireza Shahin‐Shamsabadi; Ponnambalam Ravi Selvaganapathy. A 3D Self‐Assembled In Vitro Model to Simulate Direct and Indirect Interactions between Adipocytes and Skeletal Muscle Cells. Advanced Biosystems 2020, 4, e2000034 .

AMA Style

Alireza Shahin‐Shamsabadi, Ponnambalam Ravi Selvaganapathy. A 3D Self‐Assembled In Vitro Model to Simulate Direct and Indirect Interactions between Adipocytes and Skeletal Muscle Cells. Advanced Biosystems. 2020; 4 (6):e2000034.

Chicago/Turabian Style

Alireza Shahin‐Shamsabadi; Ponnambalam Ravi Selvaganapathy. 2020. "A 3D Self‐Assembled In Vitro Model to Simulate Direct and Indirect Interactions between Adipocytes and Skeletal Muscle Cells." Advanced Biosystems 4, no. 6: e2000034.

Journal article
Published: 31 March 2020 in Chemical Engineering Science
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The anode surface is known to play an important role in the microbial growth and in mediating electron transfer between electroactive bacteria and the electrodes in power generating microbial fuel cells (MFCs). However, the effect of the anode surface and its modification on MFC-based biosensor performance has not been studied previously. In this study, our results show that the surface modification influences certain aspect of the biosensor performance. Plasma treatment makes the carbon cloth electrode hydrophilic with contact angle of 82 ± 5° from that of 139 ± 3° without treatment which consequently increases the amount of biofilm and produces higher current generation. Carbon nanotube (CNT) treatment doesn’t increase the amount of biofilm but significantly changes its electroactive microorganism composition from 2.3% to 17.3% that improves current generation. Interestingly, the sensitivity of the MFC sensor was not improved by either of these treatments. These findings would be important for the optimized design and manufacturing of biosensing MFCs.

ACS Style

Nan Xiao; Rong Wu; Jinhui Jeanne Huang; P. Ravi Selvaganapathy. Anode surface modification regulates biofilm community population and the performance of micro-MFC based biochemical oxygen demand sensor. Chemical Engineering Science 2020, 221, 115691 .

AMA Style

Nan Xiao, Rong Wu, Jinhui Jeanne Huang, P. Ravi Selvaganapathy. Anode surface modification regulates biofilm community population and the performance of micro-MFC based biochemical oxygen demand sensor. Chemical Engineering Science. 2020; 221 ():115691.

Chicago/Turabian Style

Nan Xiao; Rong Wu; Jinhui Jeanne Huang; P. Ravi Selvaganapathy. 2020. "Anode surface modification regulates biofilm community population and the performance of micro-MFC based biochemical oxygen demand sensor." Chemical Engineering Science 221, no. : 115691.

Journal article
Published: 11 March 2020 in Micromachines
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Microinjection is an established and reliable method to deliver transgenic constructs and other reagents to specific locations in C. elegans worms. Specifically, microinjection of a desired DNA construct into the distal gonad is the most widely used method to generate germ-line transformation of C. elegans. Although, current C. elegans microinjection method is effective to produce transgenic worms, it requires expensive multi degree of freedom (DOF) micromanipulator, careful injection alignment procedure and skilled operator, all of which make it slow and not suitable for scaling to high throughput. A few microfabricated microinjectors have been developed recently to address these issues. However, none of them are capable of immobilizing a freely mobile animal such as C. elegans worm using a passive immobilization mechanism. Here, a microfluidic microinjector was developed to passively immobilize a freely mobile animal such as C. elegans and simultaneously perform microinjection by using a simple and fast mechanism for needle actuation. The entire process of the microinjection takes ~30 s which includes 10 s for worm loading and aligning, 5 s needle penetration, 5 s reagent injection and 5 s worm unloading. The device is suitable for high-throughput and can be potentially used for creating transgenic C. elegans.

ACS Style

Reza Ghaemi; Justin Tong; Bhagwati P. Gupta; P. Ravi Selvaganapathy. Microfluidic Device for Microinjection of Caenorhabditis elegans. Micromachines 2020, 11, 295 .

AMA Style

Reza Ghaemi, Justin Tong, Bhagwati P. Gupta, P. Ravi Selvaganapathy. Microfluidic Device for Microinjection of Caenorhabditis elegans. Micromachines. 2020; 11 (3):295.

Chicago/Turabian Style

Reza Ghaemi; Justin Tong; Bhagwati P. Gupta; P. Ravi Selvaganapathy. 2020. "Microfluidic Device for Microinjection of Caenorhabditis elegans." Micromachines 11, no. 3: 295.

Preprint content
Published: 25 February 2020
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Premature neonates suffer from respiratory morbidity as their lungs are immature and current supportive treatment such as mechanical ventilation or extracorporeal membrane oxygenation (ECMO) cause iatrogenic injuries. A non-invasive and biomimetic concept known as the “artificial placenta” would be beneficial to overcome complications associated with the current respiratory support of preterm infants. Here, a pumpless oxygenator connected to the systemic circulation supports the lung function to relieve respiratory distress. In this paper, we demonstrate the first successful operation of a microfluidic, artificial placenta type neonatal lung assist device (LAD) on a newborn piglet model which is the closest representation of preterm human infants. This LAD has high oxygenation capability in both pure oxygen and room air as the sweep gas. It was able to relieve the respiratory distress that the newborn piglet was put under during experimentation, repeatedly and over significant duration of time. These findings indicate that this LAD has potential application as a biomimetic artificial placenta to support respiratory needs of preterm neonates.

ACS Style

Mohammadhossein Dabaghi; Niels Rochow; Neda Saraei; Gerhard Fusch; Shelley Monkman; Kevin Da; Alireza Shahin-Shamsabadi; John L. Brash; Dragos Predescu; Kathleen Delaney; Christoph Fusch; Ponnambalam Ravi Selvaganapathy. A Pumpless Microfluidic Neonatal Lung Assist Device for Support of Preterm Neonates in Respiratory Distress. 2020, 1 .

AMA Style

Mohammadhossein Dabaghi, Niels Rochow, Neda Saraei, Gerhard Fusch, Shelley Monkman, Kevin Da, Alireza Shahin-Shamsabadi, John L. Brash, Dragos Predescu, Kathleen Delaney, Christoph Fusch, Ponnambalam Ravi Selvaganapathy. A Pumpless Microfluidic Neonatal Lung Assist Device for Support of Preterm Neonates in Respiratory Distress. . 2020; ():1.

Chicago/Turabian Style

Mohammadhossein Dabaghi; Niels Rochow; Neda Saraei; Gerhard Fusch; Shelley Monkman; Kevin Da; Alireza Shahin-Shamsabadi; John L. Brash; Dragos Predescu; Kathleen Delaney; Christoph Fusch; Ponnambalam Ravi Selvaganapathy. 2020. "A Pumpless Microfluidic Neonatal Lung Assist Device for Support of Preterm Neonates in Respiratory Distress." , no. : 1.

Journal article
Published: 07 February 2020 in Sensors
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Electrodeposition is a versatile technique for the fabrication of electrodes in micro-electroanalytical devices. Conductive but low-cost materials, such as copper, can be coated with functional yet higher-cost materials such as gold or silver using electrodeposition to lower the overall cost while maintaining functionality. When the electrodeposition of multiple materials is required, current methods use a multistep process that deposits one material at a time, which requires a significant amount of time and a significant number of steps. Additionally, they use a large volume of electrolytes suitable for coating large objects, which is wasteful and unnecessary for the prototyping or coating of microelectrodes with a small area. In this paper, a new method of electroplating is introduced in which we used gels to immobilize and pattern electroplating electrolytes on a substrate surface. Agarose, as an immobilizing medium, enables the immersion of the substrate in a common working electrolyte without cross-mixing different electrolytes. We demonstrate the printing of jelly electrolytes by using spot-dispensing or microfluidic flow. Xurographically patterned films laminated on the substrate function as a mask and confine the printed gels to desired locations. After printing, the substrate is placed in a common working electrolyte container, and multimaterial patterns are produced through the application of an electrical current in a single step.

ACS Style

Aliakbar Mohammadzadeh; Alison Fox-Robichaud; P. Ravi Selvaganapathy. Electroplating of Multiple Materials in Parallel Using Patterned Gels with Applications in Electrochemical Sensing. Sensors 2020, 20, 886 .

AMA Style

Aliakbar Mohammadzadeh, Alison Fox-Robichaud, P. Ravi Selvaganapathy. Electroplating of Multiple Materials in Parallel Using Patterned Gels with Applications in Electrochemical Sensing. Sensors. 2020; 20 (3):886.

Chicago/Turabian Style

Aliakbar Mohammadzadeh; Alison Fox-Robichaud; P. Ravi Selvaganapathy. 2020. "Electroplating of Multiple Materials in Parallel Using Patterned Gels with Applications in Electrochemical Sensing." Sensors 20, no. 3: 886.

Journal article
Published: 12 December 2019 in Journal of Membrane Science
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Traditionally, cylindrical hollow fibers have been used as gas exchange interfaces in commercial oxygenators due to their simplicity of fabrication and the ability to oxygenate a large volume of blood by flowing blood around a bundle of cylindrical hollow fibers, which are served for the introduction of the gases. Over the past decade, newer microfluidic designs have been developed to overcome some of the limitations of the hollow fiber technology such as the lack of the ability to provide biomimetic flow paths to reduce shear stress and hence potentially initiation of the blood coagulation cascade as well as the difficulty to reduce the distance between fibers to decrease the resistance to diffusion of gases on the blood compartment while achieving higher efficiency of gas exchange. Nevertheless, the microfluidic designs that have been reported in the literature only provide gas exchange interfaces on one or two sides of their rectangular cross-section blood perfusion channels, thereby limiting gas exchange efficiency. Here, we report on a new design where closed gas chambers are placed adjacent to the blood perfusion channels so that the gas exchange into the blood can occur on all four sides. We demonstrate that such a design will increase the gas exchange surface area without affecting the channel's geometry or its flow characteristics. The gas exchange performance of the new design is enhanced up to 223% Compared with its equivalent double-sided gas exchange design. These new designs are expected, in the future, to help microfluidic oxygenators combine the best characteristics of both the microfluidic and hollow fiber designs to achieve superior performance.

ACS Style

Mohammadhossein Dabaghi; Neda Saraei; Gerhard Fusch; Niels Rochow; John L. Brash; Christoph Fusch; P. Ravi Selvaganapathy. Microfluidic blood oxygenators with integrated hollow chambers for enhanced air exchange from all four sides. Journal of Membrane Science 2019, 596, 117741 .

AMA Style

Mohammadhossein Dabaghi, Neda Saraei, Gerhard Fusch, Niels Rochow, John L. Brash, Christoph Fusch, P. Ravi Selvaganapathy. Microfluidic blood oxygenators with integrated hollow chambers for enhanced air exchange from all four sides. Journal of Membrane Science. 2019; 596 ():117741.

Chicago/Turabian Style

Mohammadhossein Dabaghi; Neda Saraei; Gerhard Fusch; Niels Rochow; John L. Brash; Christoph Fusch; P. Ravi Selvaganapathy. 2019. "Microfluidic blood oxygenators with integrated hollow chambers for enhanced air exchange from all four sides." Journal of Membrane Science 596, no. : 117741.

Journal article
Published: 16 November 2019 in Sensors and Actuators B: Chemical
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The rapid quantification of biological oxygen demand (BOD) plays an important role in environmental management, for instance, wastewater treatment. This study used xurographic fabrication technology to rapidly fabricate a low cost miniaturized microbial fuel cell (MFC) and demonstrated its suitability to measure BOD. The miniaturized sensor could be fabricated in 10 min with low cost of $0.5 U.S. per device. The reaction volume was designed to be 1.8 μL to obtain faster response time. The sensor was tested using sodium acetate (NaAc) as a model BOD analyte. It could response to a wide range of BOD concentration between 20 and 490 mg/L which would cover the majority range of wastewater BOD concentration in a wastewater treatment plant. The response time of this microsensor was 1.1 min which was significantly shorter than other conventional methods for BOD measurements (5 days). This study demonstrated that the use of xurographic methods to fabricate MFCs could enable rapid fabrication of microsensors to measure BOD in a rapid manner. This study also identified the potential of the sensor for application in wastewater treatment plants to monitor BOD and provide guidance for controlling treatment processes.

ACS Style

Nan Xiao; Rong Wu; Jinhui Jeanne Huang; P. Ravi Selvaganapathy. Development of a xurographically fabricated miniaturized low-cost, high-performance microbial fuel cell and its application for sensing biological oxygen demand. Sensors and Actuators B: Chemical 2019, 304, 127432 .

AMA Style

Nan Xiao, Rong Wu, Jinhui Jeanne Huang, P. Ravi Selvaganapathy. Development of a xurographically fabricated miniaturized low-cost, high-performance microbial fuel cell and its application for sensing biological oxygen demand. Sensors and Actuators B: Chemical. 2019; 304 ():127432.

Chicago/Turabian Style

Nan Xiao; Rong Wu; Jinhui Jeanne Huang; P. Ravi Selvaganapathy. 2019. "Development of a xurographically fabricated miniaturized low-cost, high-performance microbial fuel cell and its application for sensing biological oxygen demand." Sensors and Actuators B: Chemical 304, no. : 127432.