The National Institutes of Health recently awarded $2.3 million to researchers at the University of Michigan at Ann Arbor to help them develop a portable, biochip-based HIV/AIDS testing device to be used in the developing world.
The grant is one of several awarded under the American Recovery and Reinvestment Act of 2009 to projects developing microarray or microfluidic biochip-based detection systems for pathogen identification applications.
According to Nikos Chronis, an investigator in the department of mechanical engineering at UMich, the aim of the project is to develop a "portable, inexpensive, microelectromechanical systems-based imaging system for counting the absolute number of CD4 cells from whole blood samples from patients with HIV/AIDS."
Chronis told BioArray News this week that while highly active antiretroviral therapies are being made available in some cases to patients with HIV/AIDS in developing countries, in such resource-limited settings there are no diagnostics available for evaluating the efficacy of those therapies.
Chronis' point-of-care device will be designed to monitor disease activity in HIV-positive individuals by counting CD4+ T cells. But rather than reading cells one by one, Chronis said his system can image thousands of individual cells that are pre-assembled on the surface of a biochip.
The ultimate goal of his lab is to "develop a system that can reach the end user wherever limited infrastructure is present and no access to a hospital or clinic is possible."
Chronis said that the recent NIH stimulus funding should be able to help his lab develop a prototype sometime within the next three years. Then his lab will study the efficacy of the device in human subjects while evaluating different commercial paths for the platform.
"Microtechnology is portable and miniaturized and things can be done in-field, so there's a need for it and it's a perfect match for technology in the developing world," Chronis said. "The device I am developing is aimed to be used by developing countries where the main issue is the cost."
Chronis added that it would be largely up to non-governmental organizations to adopt the system once it becomes available.
"We are relying mainly on NGOs. It has to be very cheap. It has to be $3 per test or so," he said. "But the market is huge; there are 30 million people that need to be monitored. This could become the gold-standard test for Africa."
Chronis said that after the HIV-monitoring application is developed, he could adapt the biochip for other applications. "I have some other ideas for modifying the design for pathogen identification," Chronis said. "You could capture or count virus particles within a chip, for example."
Chronis' project is one of several related to pathogen detection to receive NIH stimulus funding. According to an analysis conducted earlier this month by BioArray News, the NIH awarded more than $5 million to pathogen detection-related projects out of a total of $76 million awarded to projects involving microarrays or microfluidic biochips (see BAN 10/13/2009).
Like Chronis, Bowling Green State University's Pavel Anzenbacher received $203,000 in stimulus financing to create self-luminant microarrays and a portable reader for rapid, point-of-care diagnostics.
According to the grant abstract, Anzenbacher's goal is to generate a "fluorescence-based microarray diagnostic platform and a rugged device" capable of reading DNA and protein microarrays for performing the routine array-based comprehensive DNA, protein, or pathogen analysis.
Specifically, Anzenbacher will develop disposable, self-illuminated array slides with integrated backlighting and a portable microarray reader. The self-illuminated microarray slides will consist of commercial Agilent slides that include fabricated resonant microcavity organic light-emitting diodes as a light source designed to selectively excite a fluorescent label.
[ pagebreak ]
In the abstract, Anzenbacher said the illuminated arrays could "effectively replace the expensive lasers in current array scanners."
His lab is aiming at producing a prototype that costs less than $5,000. The ultimate goal of his effort will be to make the platform available in "field hospitals, poor countries, war zones, mountainous, and other inaccessible localities or natural-disaster areas."
Anzenbacher told BioArray News this week that it was likely his lab would require additional funding to see the project through to completion. The $203,000 grant "may sound like a lot, but in fact we may not be able to accomplish much," he said. "I would say that the chance at developing a technology [with this amount alone] is small."
Brown University researcher Anubhav Tripathi also received NIH stimulus funding to develop a portable biochip-based device for influenza subtyping. According to the abstract of the grant, Tripathi plans to develop an influenza-detection microchip capable of identifying sequence-specific influenza subtypes.
The device "accepts clinical specimens from mucosal swabs and isolates influenza virus RNA based on conserved consensus sequences to complementary DNA oligonucleotides immobilized on microbeads," according to the abstract.
The sequences are used as templates for reverse transcription using a nucleic acid sequence-based amplification mechanism inside the chamber of a packed-bed microchip, Tripathi said in the abstract.
The transcription products of the continuous flow reaction are sequentially mixed with a flow stream containing dual probes specific for one of each of the repertoire of possible sequences. The dual probes fluoresce only when specifically hybridized with the complementary viral sequence. A low-cost camera records the downstream detection area to collect the transient signal to identify the viral subtype, and the results are then compared to the positive and negative controls.
According to Tripathi, the proposed device is being designed for use "outside of core laboratories."