3D printed microfluidic device for point-of-care anemia diagnosis

Master of ScienceDepartment of Biological & Agricultural EngineeringMei HeAnemia affects about 25% of the world’s population and causes roughly 8% of all disability cases. The development of an affordable point-of-care (POC) device for detecting anemia could be a significant for individuals in underdeveloped countries trying to manage their anemia. The objective of this study was to design and fabricate a 3D printed, low cost microfluidic mixing chip that could be used for the diagnosis of anemia. Microfluidic mixing chips use capillary flow to move fluids without the aid of external power. With new developments in 3D printing technology, microfluidic devices can be fabricated quickly and inexpensively. This study designed and demonstrated a passive microfluidic mixing chip that used capillary force to mix blood and a hemoglobin detecting assay. A 3D computational fluid dynamic simulation model of the chip design showed 96% efficiency when mixing two fluids. The mixing chip was fabricated using a desktop 3D printer in one hour for less than $0.50. Blood samples used for the clinical validation were provided by The University of Kansas Medical Center Biospecimen Repository. During clinical validation, RGB (red, green, blue) values of the hemoglobin detection assay color change within the chip showed consistent and repeatable results, indicating the chip design works efficiently as a passive mixing device. The anemia detection assay tended to overestimate hemoglobin levels at lower values while underestimating them in higher values, showing the assay needs to go through more troubleshooting

3D Printed Microfluidic Devices

3D printing has revolutionized the microfabrication prototyping workflow over the past few years. With the recent improvements in 3D printing technologies, highly complex microfluidic devices can be fabricated via single-step, rapid, and cost-effective protocols as a promising alternative to the time consuming, costly and sophisticated traditional cleanroom fabrication. Microfluidic devices have enabled a wide range of biochemical and clinical applications, such as cancer screening, micro-physiological system engineering, high-throughput drug testing, and point-of-care diagnostics. Using 3D printing fabrication technologies, alteration of the design features is significantly easier than traditional fabrication, enabling agile iterative design and facilitating rapid prototyping. This can make microfluidic technology more accessible to researchers in various fields and accelerates innovation in the field of microfluidics. Accordingly, this Special Issue seeks to showcase research papers, short communications, and review articles that focus on novel methodological developments in 3D printing and its use for various biochemical and biomedical applications

Innovative miniaturized electroanalytical approaches for the analysis of clinically relevant glycoproteins

El objetivo principal de esta Tesis Doctoral ha sido el desarrollo de nuevas herramientas y estrategias electroquímicas (ultra)-miniaturizadas (sensores serigrafiados y sistemas microfluídicos), combinadas con nanomateriales como transductores electroquímicos, para la determinación de biomarcadores glicoproteicos de gran relevancia en el diagnóstico de enfermedades. En el contexto del diagnóstico clínico actual, existe una tendencia hacia el diseño y desarrollo de dispositivos portátiles que permitan el análisis descentralizado de los laboratorios clínicos, y que puede quedar englobada bajo el término POCT (de sus siglas en inglés Point-of-Care Testing). Este término describe aquellas pruebas o ensayos que se realizan en lo que podría denominarse en el punto de necesidad (cerca o por el propio del paciente, incluso de forma remota). Además de los desarrollos propios de la electrónica, el desarrollo y éxito de la tecnología POCT ha dependido y depende en gran medida del diseño y desarrollo de nuevas tecnologías analíticas (ultra)-miniaturizadas. Los dispositivos basados en la transducción electroquímica han resultado ser esenciales en el desarrollo de (bio)-sensores, produciendo plataformas simples, pero precisas y sensibles, para el diagnóstico de enfermedades y ha sido uno de los enfoques más prometedores para el desarrollo de POCTs, debido en general a su instrumentación económica y a su fácil miniaturización. Esta Tesis Doctoral aborda el análisis de dos glicoproteínas: la alfa-1-ácido glicoproteína (AGP) y la transferrina (Tf). La primera se utiliza como biomarcador glicoproteico de procesos inflamatorios, y la segunda como biomarcador de una enfermedad rara denominada trastornos congénitos de la glicosilación (CDG). La detección electroquímica puede ser una buena alternativa para la determinación de glicoproteínas debido a su miniaturización inherente, sus elevadas sensibilidad y selectividad y su bajo coste. Sin embargo, la oxidación directa de las glicoproteínas presenta baja sensibilidad debido a que los carbohidratos presentes en las mismas son electroquímicamente inactivos en condiciones cercanas a las fisiológicas. Para paliar este inconveniente, se ha propuesto el uso de complejos de osmio (VI) con ligandos nitrogenados [Os (VI) L] como sonda electroquímica. El complejo de osmio (VI) reacciona con los grupos diol de los carbohidratos formándose un éster de osmato que produce dos señales electroquímicas en electrodos de carbono. El objetivo de la Tesis Doctoral ha sido el diseño y desarrollo de dos tipos de herramientas analíticas (ultra)-miniaturizadas compatibles con la tecnología POCT, sensores y sistemas microfluídicos electroquímicos, para el análisis de las glicoproteínas seleccionadas, AGP y Tf. En efecto, de forma específica se proponen, de forma evolutiva en lo que a las prestaciones analíticas requeridas por un POCT electroquímico se refiere: i) sensores electroquímicos serigrafiados basados en carbono y en carbono nanoestructurado para el análisis individual de las glicoproteínas, ii) microchip de electroforesis capilar para el análisis simultáneo de ambas y, iii) nuevos dispositivos microfluídicos desechables de flujo pasivo y con capacidad de integración de las etapas analíticas para la determinación individual de las glicoproteínas. Las herramientas electroquímicas desarrolladas han permitido no sólo la determinación rápida, fiable, in situ y con bajo coste de estos biomarcadores relevantes en el diagnóstico clínico de importantes enfermedades, sino un avance conceptual hacia la descentralización del análisis clínico y, por ende, una mejora del diagnóstico actua

Microfluidics for Biosensing

There are 12 papers published with 8 research articles, 3 review articles and 1 perspective. The topics cover: Biomedical microfluidics Lab-on-a-chip Miniaturized systems for chemistry and life science (MicroTAS) Biosensor development and characteristics Imaging and other detection technologies Imaging and signal processing Point-of-care testing microdevices Food and water quality testing and control We hope this collection could promote the development of microfluidics and point-of-care testing (POCT) devices for biosensing

CD-based microfluidics for primary care in extreme point-of-care settings

We review the utility of centrifugal microfluidic technologies applied to point-of-care diagnosis in extremely under-resourced environments. The various challenges faced in these settings are showcased, using areas in India and Africa as examples. Measures for the ability of integrated devices to effectively address point-of-care challenges are highlighted, and centrifugal, often termed CD-based microfluidic technologies, technologies are presented as a promising platform to address these challenges. We describe the advantages of centrifugal liquid handling, as well as the ability of a standard CD player to perform a number of common laboratory tests, fulfilling the role of an integrated lab-on-a-CD. Innovative centrifugal approaches for point-of-care in extremely resource-poor settings are highlighted, including sensing and detection strategies, smart power sources and biomimetic inspiration for environmental control. The evolution of centrifugal microfluidics, along with examples of commercial and advanced prototype centrifugal microfluidic systems, is presented, illustrating the success of deployment at the point-of-care. A close fit of emerging centrifugal systems to address a critical panel of tests for under-resourced clinic settings, formulated by medical experts, is demonstrated. This emphasizes the potential of centrifugal microfluidic technologies to be applied effectively to extremely challenging point-of-care scenarios and in playing a role in improving primary care in resource-limited settings across the developing world

Particles Separation in Microfluidic Devices, Volume II

Microfluidic platforms are increasingly being used for separating a wide variety of particles based on their physical and chemical properties. In the past two decades, many practical applications have been found in chemical and biological sciences, including single cell analysis, clinical diagnostics, regenerative medicine, nanomaterials synthesis, environmental monitoring, etc. In this Special Issue, we invited contributions to report state-of-the-art developments in the fields of micro- and nanofluidic separation, fractionation, sorting, and purification of all classes of particles, including, but not limited to, active devices using electric, magnetic, optical, and acoustic forces; passive devices using geometries and hydrodynamic effects at the micro/nanoscale; confined and open platforms; label-based and label-free technology; and separation of bioparticles (including blood cells), circulating tumor cells, live/dead cells, exosomes, DNA, and non-bioparticles, including polymeric or inorganic micro- and nanoparticles, droplets, bubbles, etc. Practical devices that demonstrate capabilities to solve real-world problems were of particular interest

Improved Tools for Point-of-Care Nucleic Acid Amplification Testing

There is a critical need for improved diagnostic tools to detect infectious diseases, especially in low-resource regions. A sample-to-answer point-of-care nucleic acid amplification test (NAAT) would be incredibly valuable for many different applications (e.g. COVID-19, Chlamydia/Gonorrhoeae, Influenza, Ebola, Zika/Chikungunya/Dengue, etc.). However, sample preparation (purification of pure nucleic acids) is a challenging bottleneck. In Chapter 2, commercial NA extraction methods were studied and improved. In Chapter 3, commercial stocks of SARS-CoV-2 RNA used in FDA emergency-use authorizations were found to be inaccurate and were independently quantified using reverse transcription digital PCR. In Chapter 4, a 3D printed meter-mix device was developed for initial processing prior to the sample preparation device. In Chapter 5, a 3D printed sample-to-device interface was prototyped to facilitate loading multi-volume SlipChip devices with purified template mixed with LAMP reactants. In Chapters 6-7, advancements were made for image processing of commercial chips to study digital LAMP reactions. In Chapter 8, additional tools were developed towards sample-to-answer point-of-care NAAT including a sample preparation module, amplification module, cell-phone readout, and automated base station

Design, Fabrication and Characterization

Funding Information: This work was financed by national funds from FCT, Fundação para a Ciência e a Tecnologia, I.P., in the scope of the projects LA/P/0037/2020, UIDP/50025/2020, and UIDB/50025/2020 of the Associate Laboratory Institute of Nanostructures, Nanomodelling and Nanofabrication, i3N, and also under project dPCR4FreeDNA of the same research unit, PTDC/BTM-SAL/31201/2017. Furthermore, the work received funding from FCT in the scope of projects UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences, UCIBIO, and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy, i4HB. B. J. Coelho acknowledges FCT for the attribution of grant SFRH/BD/132904/2017 and grant COVID/BD/152453/2022. Publisher Copyright: © 2023 by the authors.Microfluidic-based platforms have become a hallmark for chemical and biological assays, empowering micro- and nano-reaction vessels. The fusion of microfluidic technologies (digital microfluidics, continuous-flow microfluidics, and droplet microfluidics, just to name a few) presents great potential for overcoming the inherent limitations of each approach, while also elevating their respective strengths. This work exploits the combination of digital microfluidics (DMF) and droplet microfluidics (DrMF) on a single substrate, where DMF enables droplet mixing and further acts as a controlled liquid supplier for a high-throughput nano-liter droplet generator. Droplet generation is performed at a flow-focusing region, operating on dual pressure: negative pressure applied to the aqueous phase and positive pressure applied to the oil phase. We evaluate the droplets produced with our hybrid DMF–DrMF devices in terms of droplet volume, speed, and production frequency and further compare them with standalone DrMF devices. Both types of devices enable customizable droplet production (various volumes and circulation speeds), yet hybrid DMF–DrMF devices yield more controlled droplet production while achieving throughputs that are similar to standalone DrMF devices. These hybrid devices enable the production of up to four droplets per second, which reach a maximum circulation speed close to 1540 µm/s and volumes as low as 0.5 nL.publishersversionpublishe

Pharmachk: robust device for counterfeit and substandard medicines screening on developing regions

Thesis (Ph.D.)--Boston UniversityCounterfeit and substandard medicines are a grave public health concern that comprises a $75B black market and claims over 100,000 lives every year. The World Health Organization estimates that 10-50% of medicines in countries around the world are adulterated, and their presence imposes serious financial and economic burdens while also contributing to the rise of drug-resistant pathogens. Although a plethora of technologies are available for field-based quality screening, none reliably quantify active pharmaceutical ingredient (API) content or kinetic release from a dissolving tablet. The United States Pharmacopeia, a global leader in medicines standards for over 150 years, indicates that these quality measures are vitally important yet remain outside of the reach ofexisting screening tools. The current field standard relies on thin layer chromatography to only provide qualitative results that make it difficult to discern between tablets that contain 80% and 100% API. Meanwhile, international standards set the threshold for substandard medicines at 90%. This clear lack of appropriately quantitative and field- ready analytical tools poses a serious problem for national and international policymakers who are plagued with wildly variable information that prevents focused and deliberate action against the spread ofthese medications. This work presents an alternative analytical technique that can specifically and accurately quantify drug API content and kinetic release. PharmaChk provides an orthogonal approach to existing technologies using a portable, inexpensive, and easy-to-use platform. We demonstrate that aptamers can provide a simple and effective way to target a wide range of APis, while maintaining high quantitative precision and accuracy. A microfluidic, flow-through system is employed to obtain valuable drug quality information using a single step procedure. Through our research, we demonstrate the development of the PharmaChk platform from the proof-of-concept stage to beta prototyping and field-testing. By providing a portable, robust, and quantitative approach to medicines testing, PharmaChk can enable the collection of important drug quality information throughout pharmaceutical supply chains and ultimately save the lives of millions that are not afforded safe and essential medicines