Development of a microfluidic system for measuring HIV-1 viral load

Advances in Continuous Microfluidics-Based Technologies for the Study of HIV Infection

HIV-1 is the causative agent of acquired immunodeficiency syndrome (AIDS). It affects millions of people worldwide and the pandemic persists despite the implementation of highly active antiretroviral therapy. A wide spectrum of techniques has been implemented in order to diagnose and monitor AIDS progression over the years. Besides the conventional approaches, microfluidics has provided useful methods for monitoring HIV-1 infection. In this review, we introduce continuous microfluidics as well as the fabrication and handling of microfluidic chips. We provide a review of the different applications of continuous microfluidics in AIDS diagnosis and progression and in the basic study of the HIV-1 life cycle.

A confirmatory test for sperm in sexual assault samples using a microfluidic-integrated cell phone imaging system

Rapid and efficient processing of sexual assault evidence to accelerate forensic investigation and decrease casework backlogs is urgently needed. Therefore, the standardized protocols currently used in forensic laboratories can benefit from continued innovation to handle the increasing number and complexity of samples being submitted to forensic labs. To our knowledge, there is currently no available rapid and portable forensic screening technology based on a confirmatory test for sperm identification in a sexual assault kit. Here, we present a novel forensic sample screening tool, i.e., a microchip integrated with a portable cell phone imaging platform that records and processes images for further investigation and storage. The platform (i) precisely and rapidly screens swab samples (<15 min after sample preparation on-chip); (ii) selectively captures sperm from mock sexual assault samples using a novel and previously published SLeX-based surface chemistry treatment (iii) separates non-sperm contents (epithelial cells and debris in this case) out of the channel by flow prior to imaging; (iv) captures cell phone images on a portable cellphone-integrated imaging platform, (v) quantitatively differentiates sperm cells from epithelial cells, using a morphology detection code that leverages Laplacian of Gaussian and Hough gradient transform methods; (vi) is sensitive within a forensic cut-off (>95% accuracy) compared to the manual counts; (vii) provides a cost-effective and timely solution to a problem which in the past has taken a great deal of time; and (viii) handles small volumes of sample (20 μL). This integration of the cellphone imaging platform and cell recognition algorithms with disposable microchips can be a new direction toward a direct visual test to screen and differentiate sperm from epithelial cell types in forensic samples for a crime laboratory scenario. With further development, this integrated platform could assist a sexual assault nurse examiner (SANE) in a hospital or sexual assault treatment center facility to flag sperm-containing samples prior to further downstream testing.

3D-Printed Lab-on-a-Chip Diagnostic Systems-Developing a Safe-by-Design Manufacturing Approach

The aim of this study is to provide a detailed strategy for Safe-by-Design (SbD) 3D-printed lab-on-a-chip (LOC) device manufacturing, using Fused Filament Fabrication (FFF) technology. First, the applicability of FFF in lab-on-a-chip device development is briefly discussed. Subsequently, a methodology to categorize, identify and implement SbD measures for FFF is suggested. Furthermore, the most crucial health risks involved in FFF processes are examined, placing the focus on the examination of ultrafine particle (UFP) and Volatile Organic Compound (VOC) emission hazards. Thus, a SbD scheme for lab-on-a-chip manufacturing is provided, while also taking into account process optimization for obtaining satisfactory printed LOC quality. This work can serve as a guideline for the effective application of FFF technology for lab-on-a-chip manufacturing through the safest applicable way, towards a continuous effort to support sustainable development of lab-on-a-chip devices through cost-effective means.

Point-of-care microfluidic devices for pathogen detection

The rapid diagnosis of pathogens is crucial in the early stages of treatment of diseases where the choice of the correct drug can be critical. Although conventional cell culture-based techniques have been widely utilized in clinical applications, newly introduced optical-based, microfluidic chips are becoming attractive. The advantages of the novel methods compared to the conventional techniques comprise more rapid diagnosis, lower consumption of patient sample and valuable reagents, easy application, and high reproducibility in the detection of pathogens. The miniaturized channels used in microfluidic systems simulate interactions between cells and reagents in microchannel structures, and evaluate the interactions between biological moieties to enable diagnosis of microorganisms. The overarching goal of this review is to provide a summary of the development of microfluidic biochips and to comprehensively discuss different applications of microfluidic biochips in the detection of pathogens. New types of microfluidic systems and novel techniques for viral pathogen detection (e.g. HIV, HVB, ZIKV) are covered. Next generation techniques relying on high sensitivity, specificity, lower consumption of precious reagents, suggest that rapid generation of results can be achieved via optical based detection of bacterial cells. The introduction of smartphones to replace microscope based observation has substantially improved cell detection, and allows facile data processing and transfer for presentation purposes.

Micro- and nanotechnology for HIV/AIDS diagnostics in resource-limited settings

Thirty-four million people are living with HIV worldwide, a disproportionate number of whom live in resource-limited settings. Proper clinical management of AIDS, the disease caused by HIV, requires regular monitoring of both the status of the host's immune system and levels of the virus in their blood. Therefore, more accessible technologies capable of performing a CD4+ T cell count and HIV viral load measurement in settings where HIV is most prevalent are desperately needed to enable better treatment strategies and ultimately quell the spread of the virus within populations. This review discusses micro- and nanotechnology solutions to performing these key clinical measurements in resource-limited settings.

Advances in developing HIV-1 viral load assays for resource-limited settings

Commercial HIV-1 RNA viral load assays have been routinely used in developed countries to monitor antiretroviral treatment (ART). However, these assays require expensive equipment and reagents, well-trained operators, and established laboratory infrastructure. These requirements restrict their use in resource-limited settings where people are most afflicted with the HIV-1 epidemic. Inexpensive alternatives such as the Ultrasensitive p24 assay, the reverse transcriptase (RT) assay and in-house reverse transcription quantitative polymerase chain reaction (RT-qPCR) have been developed. However, they are still time-consuming, technologically complex and inappropriate for decentralized laboratories as point-of-care (POC) tests. Recent advances in microfluidics and nanotechnology offer new strategies to develop low-cost, rapid, robust and simple HIV-1 viral load monitoring systems. We review state-of-the-art technologies used for HIV-1 viral load monitoring in both developed and developing settings. Emerging approaches based on microfluidics and nanotechnology, which have potential to be integrated into POC HIV-1 viral load assays, are also discussed.