First Long-Term Study on Medical Marijuana’s Impact on Opioid Use for Pain

The National Institutes of Health (NIH) has awarded researchers at Albert Einstein College of Medicine and Montefiore Health System a five-year, $3.8 million grant for the first long-term study to test whether medical marijuana reduces opioid use among adults with chronic pain, including those with HIV.

Millions of Americans experience chronic, severe pain as a result of their health conditions.  Many take prescribed opioids, including Oxycodone, to help relieve their symptoms. But given the dangers of opioid use and misuse, both doctors and patients are seeking safe and effective alternatives to manage pain.

“There is a lack of information about the impact of medical marijuana on opioid use in those with chronic pain,” says Chinazo Cunningham, M.D., M.S., associate chief of general internal medicine at Einstein and Montefiore and principal investigator on the grant. “We hope this study will fill in the gaps and provide doctors and patients with some much needed guidance.”

Compared to the general population, chronic pain and opioid use is even more common in people with HIV. Between 25 and 90 percent of adults with HIV suffer from chronic pain. Previous studies have reported that despite the high risk for misuse of opioid pain relievers, adults with HIV are likely to receive opioids to help manage their pain. In recent years, medical marijuana has gained recognition as a treatment option. Twenty-nine states, plus the District of Columbia, have legalized its use; in those states, chronic pain and/or HIV/AIDS are qualifying conditions for medical marijuana use.

Researchers have never studied—in any population—if the use of medical marijuana over time reduces the use of opioids. Additionally, there are no studies on how the specific chemical compounds of marijuana, tetrahydrocannabinol (THC) and cannabidiol (CBD), affect health outcomes, like pain, function, and quality of life. Most studies that have reported negative effects of long-term marijuana use have focused on illicit, rather than medical, marijuana.

“As state and federal governments grapple with the complex issues surrounding opioids and medical marijuana, we hope to provide evidence-based recommendations that will help shape responsible and effective healthcare practices and public policies,” notes Dr. Cunningham.

Dr. Cunningham will enroll 250 HIV-positive and HIV-negative adults with chronic pain who use opioids and who have received certification from their physicians to use medical marijuana, which is provided through approved dispensaries in New York State. Over 18 months, the study subjects will complete web-based questionnaires every two weeks, which will focus on pain levels and the medical and illicit use of marijuana and opioids. They’ll also provide urine and blood samples at in-person research visits every three months. In addition, in-depth interviews with a select group of these participants will explore their perceptions of how medical marijuana use affects the use of opioids.

Experimental HIV vaccine regimen is well-tolerated, elicits immune responses

Results from an early-stage clinical trial called APPROACH show that an investigational HIV vaccine regimen was well-tolerated and generated immune responses against HIV in healthy adults. The APPROACH findings, as well as results expected in late 2017 from another early-stage clinical trial called TRAVERSE, will form the basis of the decision whether to move forward with a larger trial in southern Africa to evaluate vaccine safety and efficacy among women at risk of acquiring HIV.

The APPROACH results will be presented July 24 at the 9th International AIDS Society Conference on HIV Science in Paris.

The experimental vaccine regimens evaluated in APPROACH are based on “mosaic” vaccines designed to induce immunological responses against a wide variety of HIV subtypes responsible for HIV infections globally. Different HIV subtypes, or clades, predominate in various geographic regions around the world. The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, funded pre-clinical development of these vaccines. Together with other partners, NIAID supported the APPROACH trial, which is sponsored by Janssen Vaccines & Prevention B.V., part of the Janssen Pharmaceutical Companies of Johnson & Johnson. The manufacture and clinical development of the mosaic vaccines are led by Janssen.

“A safe and effective HIV vaccine would be a powerful tool to reduce new HIV infections worldwide and help bring about a durable end to the HIV/AIDS pandemic,” said NIAID Director Anthony S. Fauci, M.D. “By exploring multiple promising avenues of vaccine development research, we expand our opportunities to achieve these goals.”

APPROACH involved nearly 400 volunteers in the United States, Rwanda, Uganda, South Africa and Thailand who were randomly assigned to receive one of seven experimental vaccine regimens or a placebo. APPROACH found that different mosaic vaccine regimens were well-tolerated and capable of generating anti-HIV immune responses in healthy, HIV-negative adults. Notably, the vaccine regimen that was most protective in pre-clinical studies in animals elicited among the greatest immune responses in the study participants. However, further research will be needed because the ability to elicit anti-HIV immune responses does not necessarily indicate that a candidate vaccine regimen can prevent HIV acquisition.

According to the researchers, the findings from APPROACH, as well as from animal studies, support further evaluation of a lead candidate regimen in a clinical trial to assess its safety and efficacy. Plans for such a clinical trial to be conducted in southern Africa are in development, with projected enrollment of 2,600 healthy, HIV-negative women. Should the larger trial move forward, it is expected to begin enrollment in late 2017 or early 2018.

In APPROACH, study participants received four vaccinations over 48 weeks: two doses of an initial, or “prime,” vaccine, followed by two doses of a booster vaccine. The experimental regimens all incorporated the same vaccine components in the prime vaccination, known as Ad26.Mos.HIV. The vaccine uses a strain of common-cold virus (adenovirus serotype 26, or Ad26), engineered so that it does not cause illness, as a vector to deliver three mosaic antigens created from genes from many HIV variants. The booster vaccination included various combinations of the Ad26.Mos.HIV components or a different mosaic component, called MVA-Mosaic, and/or two different doses of clade C HIV gp140 envelope protein containing an aluminum adjuvant to boost immune responses.

The Ad26-based mosaic vaccines were initially developed by the laboratory of NIAID grantee Dan H. Barouch, M.D., Ph.D., and Janssen. In pre-clinical studies, regimens incorporating these mosaic vaccines protected monkeys against infection with an HIV-like virus called simian human immunodeficiency virus (SHIV). The most effective prime-boost regimen reduced the risk of infection per exposure to SHIV by 94 percent and resulted in 66 percent complete protection after six exposures. Researchers identified and characterized the vaccine-induced immune responses that correlated with this protection.

“The promising, early-stage results from the APPROACH study support further evaluation of these candidate vaccines to assess their ability to protect those at risk of acquiring HIV,” said Dr. Barouch, a principal investigator for APPROACH. He also is director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center in Boston and professor of medicine at Harvard Medical School.

Following the third vaccination, most APPROACH participants had developed antibody and cellular immune responses against HIV. The different boost vaccines altered the magnitude and character of these immune responses, with the regimen that showed greatest protection in monkey studies also eliciting among the greatest immune responses in humans. The anti-HIV immune responses increased after the fourth vaccination.

The researchers conclude that further evaluation of this approach would use a regimen comprising two Ad26 mosaic primes and two boosts with Ad26 mosaic and clade C gp140. The ongoing TRAVERSE trial is comparing Ad26-based regimens containing three mosaic antigens (trivalent) with Ad26-based regimens containing four mosaic antigens (tetravalent). Results from TRAVERSE are expected in late 2017.

Computer Models Could Allow Researchers to Better Understand, Predict Adverse Drug Reactions

New computer models from North Carolina State University show how a variant of a common protein involved in human immune response binds to the antiviral drug abacavir, causing a severe life-threatening reaction known as the abacavir hypersensitivity syndrome (AHS). The work has implications for predicting severe adverse reactions caused by existing drugs and future drug candidates in subpopulations of patients.

Abacavir is a common anti-HIV drug. However, it is associated with severe allergic reactions in a fraction (5-8 percent) of patients who take it. Previous research determined that this response occurs in patients with a particular variant of a human leukocyte antigen (HLA) known as HLA-B*57:01.

Denis Fourches, assistant professor of chemistry at NC State, and his graduate student, George Van Den Driessche, wanted to know what happens at the molecular level when abacavir and other drugs interact with HLA-B*57:01.

HLA proteins reside on the surface of cells and help the immune system distinguish between its own proteins and those made by infectious agents. HLA proteins and their co-binding peptides serve as signaling proteins that communicate with T-cells, ensuring that all is well. If something foreign – a pathogen, or in this case, a drug like abacavir – binds to the HLA protein, displacing the co-binding peptide and deforming the overall shape of the molecular complex, this change is recognized by immune cells, triggering the immune response.

“There are 15,000 variants of HLA, and everyone carries some of these variants,” Fourches says. “HLA-B*57:01 is one of the first variants studied in the context of a drug-induced immune reaction. We know that it binds with abacavir, but little was understood about exactly what was happening structurally at the molecular level, especially in terms of the relationship with the co-binding peptide. This is a very complex system.”

Fourches and Van Den Driessche created a series of computer models using three-dimensional molecular docking that allowed them to look at the ways in which abacavir docks in the binding site of HLA-B*57:01 – where the co-binding peptide normally docks. The models incorporated 3D structures of abacavir, HLA-B*57:01, and several potential co-binding peptides. The researchers ran molecular modeling simulations to virtually dock abacavir in the HLA-B*57:01 active site in the absence and presence of a co-binding peptide. Finally, they virtually screened an additional set of 13 drugs, some of which are known to cause severe adverse responses that are also suspected of being linked to HLA variants.

“The models allowed us to identify key atomic interactions that cause abacavir and other drugs to bind to the HLA variant protein and ultimately trigger the immune response,” Fourches says. “When you can forecast and understand the elements of the drug that enable the binding to occur, you may be able to create new active compounds that do not have that problem.”

“Our ultimate goal is to use molecular modeling to discover and understand how different drugs can interact with the immune system via direct HLA binding interaction, so that we can better predict the side-effects of new drugs and design drugs with fewer side-effects. This is critical for the personalized medicine of tomorrow.”

Largest HIV Transmission Study Conducted

A new study has found that neither gay men nor heterosexual people with HIV transmit the virus to their partner, provided they are on suppressive antiretroviral treatment.

The PARTNER study, which is the world’s largest study of people with HIV who have had condomless sex with their HIV negative partners, was conducted by investigators from the University of Liverpool, University College London, Royal Free NHS and Rigshospitalet (one of the largest hospitals in Denmark).

This work was funded by the National Institute for Health Research (NIHR) and was sponsored by UCL (University College London).

More than 800 couples monitored

The study monitored 888 couples from 14 different European countries, in which one of the partners was on effective treatment for HIV. Of the 888 couples, 548 were heterosexual and 340 were gay men.

All the couples had sex regularly without using a condom. They have now been monitored for several years and not one instance of transmission of the virus has been recorded. The results have just been published in the prestigious Journal of the American Medical Association.

In the period following the study, a total of 11 HIV-negative partners were infected with HIV. Led by Professor Anna Maria Geretti, researchers from the University of Liverpool‘s Institute of Infection and Global Health undertook phylogenetic analyses of the 11 new HIV cases and their partners’ virus.

No HIV transmission between couples

Professor Geretti, said: “The HIV virus can be divided into several sub-groups, each with its own genetic characteristics, and this makes it possible to see whether the virus is genetically similar to a partner’s. In all cases the results showed that the virus came from someone other than the partner under treatment.

“This research is vital for us to gain an even better understanding the risks associated with this particular virus.”

Professor Jens Lundgren from Rigshospitalet, senior author of the study and head of CHIP (the Centre for Health and Infectious Diseases), said: “The results clearly show that early diagnosis of HIV and access to effective treatment are crucial for reducing the number of new HIV cases. As soon as a patient with HIV is on treatment with a suppressed viral load, the risk of transmission becomes minimal.”

More data on the way

Gay couples in the study will continue to be monitored for three more years to obtain even more data in this area for anal sex.

UMN researchers find distinct differences in structure, features of retroviruses

In the most comprehensive study of its kind, researchers in the Institute for Molecular Virology and School of Dentistry at the University of Minnesota report that most types of retroviruses have distinct, non-identical virus structures.

Researchers analyzed seven different retroviruses including two types of HIV as well as HTLV-1, a virus that causes T-cell leukemia. They also examined retroviruses that infect birds, mice, chimpanzees and fish, that can cause cancer or immunodeficiency.

“Each kind of retrovirus has distinct structural features and each assembles virus particles differently,” said Louis Mansky, Ph.D., director of the Institute for Molecular Virology, who is also a member of the Masonic Cancer Center. “Most researchers assume that all retroviruses are just like HIV, but they’re not. We cannot take a one-size-fits-all approach when studying retroviruses and discovering new strategies for antiviral treatments or vaccines.”

Mansky’s team looked at the behavior of retrovirus Gag proteins, which drive retrovirus particle formation. Once the virus enters a cell, reverse transcriptase converts the viral RNA to DNA, which subsequently creates the Gag protein.

Understanding the nature of Gag protein interactions with one another and how the structures form will help scientists better understand how and why the virus works. It will also help identify ways to target the virus and prevent it from infecting a cell in the first place.

The study examined virus-like particle size, cellular distribution and basic morphological features through three distinct microscopy techniques.

The team noted that:

– HIV-1 and HIV-2 have Gag proteins that assemble retrovirus-like particles with distinct structures and sizes, which implies that differences exist in how the two HIV types form new virus particles. – HIV and HTLV-1 particles are quite distinct from one another in appearance, which also suggests fundamental differences in virus particle assembly.

“We found significant differences among the retroviruses,” said Jessica Martin, senior Ph.D. student in the Department of Pharmacology and lead author on the study. “A parallel comparative study evaluating retroviral Gag proteins and virus particle intermediates of this size and scope has never been done before.”

The team was surprised to find that one of the retroviruses, walleye dermal sarcoma virus (WDSV), did not readily produce virus particles.The disease can affect anything from 1-30 percent of walleye in a population, depending on the location. This research could help aquatic scientists better understand how to control the disease.

“Our study helps to highlight the importance of serendipity of basic science research,” Mansky said. “We set out to learn more about the differences among two important human retroviruses, namely HIV and HTLV, which we did, but our findings also shed light on important differences among all kinds of retroviruses that could inform not only the treatment of human viral diseases but could also impact aquatic health in fisheries.”

The study findings will help serve as a foundation for studying differences among retroviruses, including HIV.

“The scientific community can build off of our findings to develop new antiviral treatments, and hopefully determine how to stop these viruses from causing deadly diseases in humans such as cancer and AIDS,” Mansky said.

A New Way to Nip AIDS in the Bud

When new AIDS virus particles bud from an infected cell, an enzyme named protease activates to help the viruses mature and infect more cells. That’s why modern AIDS drugs control the disease by inhibiting protease.

Now, University of Utah researchers found a way to turn protease into a double-edged sword: They showed that if they delay the budding of new HIV particles, protease itself will destroy the virus instead of helping it spread. They say that might lead, in about a decade, to new kinds of AIDS drugs with fewer side effects.

“We could use the power of the protease itself to destroy the virus,” says virologist Saveez Saffarian, an associate professor of physics and astronomy at the University of Utah and senior author of the study released today by PLOS Pathogens, an online journal published by the Public Library of Science.

So-called cocktails or mixtures of protease inhibitors emerged in the 1990s and turned acquired immune deficiency syndrome into a chronic, manageable disease for people who can afford the medicines. But side effects include fat redistribution in the body, diarrhea, nausea, rash, stomach pain, liver toxicity, headache, diabetes and fever.

“They have secondary effects that hurt patients,” says Mourad Bendjennat, a research assistant professor of physics and astronomy and the study’s first author. “And the virus becomes resistant to the inhibitors. That’s why they use cocktails.”

Bendjennat adds that by discovering the molecular mechanism in which protease interacts with HIV, “we are developing a new approach that we believe may be very efficient in treating the spread of HIV.”

However, he and Saffarian emphasize the research is basic, and that it will be a decade before more research might develop the approach into news AIDS treatments.

Figuring out the role of protease in HIV budding

Inside a cell infected by HIV, new virus particles are constructed largely with a protein named Gag. Protease enzymes are incorporated into new viral particles as they are built, and are thought to be activated after the new particles “bud” out of infected cell and then break off from it.

The particles start to bud from the host cell in a saclike container called a vesicle, the neck of which eventually separates from the outer membrane of the infected cell. “Once the particles are released, the proteases are activated and the particles transform into mature HIV, which is infectious,” Saffarian says.

“There is an internal mechanism that dictates activation of the protease, which is not well understood,” he adds. “We found that if we slow the budding process, the protease activates while the HIV particle is still connected to the outer membrane of host [infected] cell. As a result, it chews out all the proteins inside the budding HIV particle, and those essential enzymes and proteins leak back into the host cell. The particle continues to bud out and release from the cell, but it is not infectious anymore because it doesn’t have the enzymes it needs to mature.”

Budding HIV needs ESCRTs

The scientists found they could slow HIV particles from budding out of cells by interfering with how they interact with proteins named ESCRTs (pronounced “escorts”), or “endosomal sorting complexes required for transport.”

ESCRTs are involved in helping pinch off budding HIV particles – essentially cutting them from the infected host cell.

Saffarian says scientific dogma long has held “that messing up the interactions of the virus with ESCRTs results in budding HIV particles permanently getting stuck on the host cell membrane instead of releasing.” Bendjennat says several studies in recent years indicated that the particles do get released, casting some doubt on the long held dogma.

The new study’s significance “is about the molecular mechanism: When the ESCRT machinery is altered, there is production of viruslike particles that are noninfectious,” he says. “This study explains the molecular mechanism of that.”

“We found HIV still releases even when early ESCRT interactions are intentionally compromised, however, with a delay,” Saffarian says. “They are stuck for a while and then they release. And by being stuck for a while, they lose their internal enzymes due to early protease activation and lose their infectivity.”

Bendjennat says by delaying virus budding and speeding “when the protease gets activated, we are now capable of using it to make new released viruses noninfectious”

How the research was done

The experiments used human skin cells grown in tissue culture. It already was known that new HIV particles assemble the same way whether the infected host cell is a skin cell, certain other cells or the T-cell white blood cell infected by the virus to cause AIDS. The experiments involved both live HIV and so-called viruslike particles.

Bendjennat and Saffarian genetically engineered mutant Gag proteins. A single HIV particle is made of some 2,000 Gag proteins and 120 copies of proteins known as Gag-Pol, as well as genetic information in the form of RNA. Pol includes protease, reverse transcriptase and integrase – the proteins HIV uses to replicate.

The mutant Gag proteins were designed to interact abnormally with two different ESCRT proteins, named ALIX and Tsg101.

A new HIV particle normally takes five minutes to release from an infected cell.

When the researchers interfered with ALIX, release was delayed 75 minutes, reducing by half the infectivity of the new virus particle. When the scientists interfered with Tsg101, release was delayed 10 hours and new HIV particles were not infectious.

The scientists also showed that how fast an HIV particle releases from an infected cell depends on how much enzyme cargo it carries in the form of Pol proteins. By interfering with ESCRT proteins during virus-release experiments with viruslike particles made only of Gag protein but none of the normal Pol enzymes, the 75-minute delay shrank to only 20 minutes, and the 10-hour delay shrank to only 50 minutes.

“When the cargo is large, the virus particle needs more help from the ESCRTs to release on a timely fashion,” Saffarian says.

Because HIV carries a large cargo, it depends on ESCRTs to release from an infected cell, so ESCRTs are good targets for drugs to delay release and let HIV proteases leak back into the host cell, making new HIV particles noninfectious, he says.

Bendjennat says other researchers already are looking for drugs to block ESCRT proteins in a way that would prevent the “neck” of the budding HIV particle from pinching off or closing, thus keeping it connected to the infected cell. But he says the same ESCRTs are needed for cell survival, so such drugs would be toxic.

Instead, the new study suggests the right approach is to use low-potency ESCRT-inhibiting drugs that delay HIV release instead of blocking it, rendering it noninfectious with fewer toxic side effects, he adds.

New Research Explains Why HIV Is Not Cleared by the Immune System

Scientists at the University of North Carolina (UNC) School of Medicine and Sanford Burnham Prebys Medical Discovery Institute (SBP) have identified a human (host) protein that weakens the immune response to HIV and other viruses. The findings, published today in Cell Host & Microbe, have important implications for improving HIV antiviral therapies, creating effective viral vaccines, and advance a new approach to treat cancer.

“Our study provides critical insight on a paramount issue in HIV research: Why is the body unable to mount an efficient immune response to HIV to prevent transmission?” said Sumit Chanda, Ph.D., professor and director of SBP’s Immunity and Pathogenesis Program and co-senior author of the study. “This research shows that the host protein NLRX1 is responsible—it’s required for HIV infection and works by repressing the innate immune response.”

The innate immune response works by producing a cascade of signaling chemicals (interferons and cytokines) that trigger cytotoxic T cells to kill pathogens. Increasing evidence suggests that mounting an early, potent innate immune response is essential for the control of HIV infection, and may improve the effectiveness of vaccines.

“Importantly, we were able to show that deficiencies in NLRX1 reduce HIV replication, suggesting that the development of small molecules to modulate the innate immune response may inhibit viral transmission and promote immunity to infection,” said Chanda. “We anticipate expanding our research to identify NLRX1 inhibitors.”

How NLRX1 reduces innate immunity to HIV

Although HIV is a single-stranded RNA virus, after it infects an immune cell it’s rapidly reverse transcribed into DNA, increasing the level of DNA found in the fluid portion of a cell (cytosol). Elevated cytosolic DNA triggers a sensor called STING (stimulator of interferon genes) that turns on the innate immune response.

“Until now, the mechanism by which NLRX1 promoted HIV infection was unexplored. We have shown that NLRX1 interacts directly with STING, essentially blocking its ability to interact with an enzyme called TANK-binding kinase 1 (TBK1),” said Haitao Guo, Ph.D., senior postdoctoral research associate in the laboratory of Jenny Ting, Ph.D., a University of North Carolina Lineberger Comprehensive Cancer Center member, the William R. Kenan Jr. Professor of Microbiology and Immunology at the UNC School of Medicine and lead author of the study. “The STING-TBK1 interaction is a critical step for interferon production in response to elevated cytosolic DNA, and initiates the innate immune response.”

“This research expands our understanding of the role of host proteins in viral replication and the innate immune response to HIV infection, and can be extended to DNA viruses such as HSV and vaccinia,” added Guo.

Relevance to cancer

“Our discovery that NLRX1 reduces the immune response to HIV is similar to the discovery of host immune checkpoints, such as PD-L1 and CTLA-1, that control the immune response to cancer,” said Ting, co-senior author of the study.

Immune checkpoints are immunological “brakes” that prevent the over-activation of the immune system on healthy cells. Tumor cells often take advantage of these checkpoints to escape detection of the immune system. Several FDA-approved drugs that target checkpoints, called checkpoint inhibitors, are now available to treat certain cancers.

“Checkpoint inhibitors have made a huge impact on cancer treatment, and significant investment by the biotech/pharmaceutical sector is being made to identify STING inhibitors as the next generation of immune-oncology therapeutics,” said Ting. “This study, showing that NLRX1 is a checkpoint of STING, sheds more light on the topic and will help advance those efforts.”

New Method Developed to Preserve Microfluidic Devices for HIV Monitoring in Developing Countries

Providing vital health care services to people in developing countries without reliable electricity, refrigeration and state-of-the-art medical equipment poses a number of challenges. Inspired by pregnancy tests, researchers from Florida Atlantic University, Stanford University, and Baskent University in Turkey, have developed a novel method to store microfluidic devices for CD4 T cell testing in extreme weather conditions for up to six months without refrigeration. Microfluidic devices with immunochemistry have broad applications in chemotherapy monitoring, transplant patient monitoring, and especially in monitoring the efficacy of antiretroviral therapy.

Results of this study were recently published in Nature Scientific Reports, “Engineering Long Shelf Life Multi-layer Biologically Active Surfaces on Microfluidic Devices for Point of Care Applications.”

“Monitoring HIV patients at point-of-care settings in resource-constrained countries like Africa is critical in knowing how their treatment is progressing and whether or not a particular drug is working the way it should be,” said Waseem Asghar, Ph.D., co-first author on the study and assistant professor of electrical engineering in the College of Engineering and Computer Science at FAU.

This research also has employed a lensless imaging method to rapidly count CD4 T cells using CMOS (complementary metal-oxide semiconductor) sensor – the same imaging sensor found in cell phone cameras. Lensless imaging technology allows rapid cell counting and does not require skilled technicians to operate, making it suitable for point-of-care settings. If produced at a large scale, the microfluidic device would cost less than $1 compared with the current cost of a CD4 assay which is about $30-$50.

“Similar to pregnancy tests that can be stored at room temperature, we investigated methods to store and preserve multi-layer, immuno-functionalized microfluidic devices in refrigeration-free settings for applications in resource-limited settings at the point-of-care,” said Utkan Demirci, Ph.D., senior author of the paper, Stanford University School of Medicine.

Current microfluidic devices used for biomedical applications to test for various diseases and conditions including HIV and cancer need to be stored at low temperatures 4 to 8 degrees centigrade) to prevent the degradation of antibodies. In addition, transporting these biomaterials is expensive and increases the assay costs.

Asghar and his colleagues used trehalose, a form of sugar that is present in some plants and animals, to preserve the microfluidic device. Since trehalose has the capability to enable plants to thrive in very harsh hot and cold conditions, they determined that it could have the same effect on multi-layer surfaces like a microfluidic device. They packaged and vacuum sealed the trelahose treated device in plastic and used a drying agent to address the effects of humidity. They exposed the device to extreme weather conditions in a laboratory environment to test its functionality and shelf-life.

Results of the study revealed that they were able to preserve the microfluidic devices over a period of six months using this method. At room temperature, they observed 90 percent specificity for up to six months.

The researchers also integrated these stabilized microfluidic devices post-reactivation with the CMOS lensless imaging technology. The captured CD4 T cells were counted rapidly and automatically from unprocessed whole blood, creating a portable, battery-operated, inexpensive, and microscope-free CD4 T cell counting platform with a long shelf-life.

“This technology also is widely applicable to global health applications when resources are limited to address viral load, sepsis, tuberculosis, malaria, as well as cancer detection. It also offers advantages in the developed world in settings such as in a primary care physician’s office or in the home setting,” said Asghar.