This blog originated as a press release from the University of Houston. Thanks to them for allowing us to repost it here.
Economical, Ultra-sensitive Biosensing in Point-of-Care Applications
When it comes to cancer detection, size matters. Traditional diagnostic imaging cannot detect tumors smaller than a certain size, causing missed opportunities for early detection and treatment. Circulating tumor exosomes are especially small cancer biomarkers and easy to miss. These nanovesicles are composed of molecules that reflect the parental cells. But, because they are tiny (~30-150nm in diameter) and complex, the precise detection of exosome-carried biomarkers with molecular specificity has been elusive, until now.
Wei-Chuan Shih, professor of electrical and computer engineering at the University of Houston Cullen College of Engineering, reports the findings in IEEE Sensors Journal.
“This work demonstrates, for the first time, that the strong synergy of arrayed radiative coupling and substrate undercut can enable high-performance biosensing in the visible light spectrum where high-quality, low-cost silicon detectors are readily available for point-of-care application,” said Shih. “The result is a remarkable sensitivity improvement, with a refractive index sensitivity increase from 207 nm/RIU to 578 nm/RIU.”
Wei-Chuan Shih, professor of electrical and computer engineering at the University of Houston, is reporting rapid cancer detection as a cost-effective, high-performance platform for molecularly specific exosome biosensing.
This blog originated as a press release from the Broad Institute of MIT and Harvard. Thanks to MIT News for allowing us to repost it here.
Made of components found in the human body, the programmable system is a step toward safer, targeted delivery of gene editing and other molecular therapeutics.
A new system to deliver molecular therapies to cells, called SEND, can be programmed to encapsulate and deliver different RNA cargoes, potentially provoking less of an immune response than other delivery approaches. Credit: Courtesy of the researchers
Researchers from MIT, the McGovern Institute for Brain Research at MIT, the Howard Hughes Medical Institute, and the Broad Institute of MIT and Harvard have developed a new way to deliver molecular therapies to cells. The system, called SEND, can be programmed to encapsulate and deliver different RNA cargoes. SEND harnesses natural proteins in the body that form virus-like particles and bind RNA, and it may provoke less of an immune response than other delivery approaches.
This blog originated as a press release from the Singopore-MIT Alliance for Research and Technology (SMART). Thanks to them for allowing us to repost it here.
Four times faster than conventional PCR methods, a new approach called RADICA is highly specific, sensitive, and resistant to inhibitors.
● RApid DIgital Crispr Approach (RADICA) is a molecular rapid testing methodology that allows absolute quantification of viral nucleic acids in 40-60 minutes.
● RADICA is four times faster and significantly less expensive than conventional polymerase chain reaction (PCR) methods as it does not require costly equipment for precise temperature control and cycling.
● The method has been tested on SARS-CoV-2 synthetic DNA and RNA, Epstein–Barr virus in human B cells and serum, and can be easily adapted to detect other kinds of viruses.
This blog originated as a press release from The Ohio State University. Thanks to them for allowing us to repost it here.
Dr. Raphael Pollock has earned the reputation as one of the world’s best surgical oncologists for patients facing one of the toughest cancers to treat, sarcoma. Frequently these tumors start out in the very deepest recesses of the retroperitoneum, the part of the abdomen where the kidneys, pancreas and inferior vena cava are located.
Dr. Raphael Pollock
Director of The Ohio State University Comprehensive Cancer Center, Pollock’s 30 years of experience in the operating room naturally led him to ponder the steps before surgery, specifically if there were better ways to diagnose or detect sarcomas. In early 2019, he tapped into Ohio State’s scientific breadth and depth to investigate a new diagnostic method based upon research he conducted while at MD Anderson Cancer Center in Houston. He reached out to Shaurya Prakash, associate professor of mechanical and aerospace engineering and an expert in microfluidics.
Currently, there are two predominant options to acquire a diagnostic biopsy of a tumor deep in the abdomen: invasive surgery under general anesthesia; or a method utilizing computed tomography (CT) scans to guide a long needle through the skin to acquire tissue from the mass. Both are expensive and take time to schedule.
“I’ve been interested for a while in the role of exosomes in the spread of cancers,” Pollock said. Exosomes are extracellular vesicles containing constituents—protein, DNA, and RNA—of the cells that secrete them. They can affect function and behavior of other cells with which they interact. Until recently, they were regarded as merely cell waste products without much clinical research relevance.
Dr. Shaurya Prakash
“We learned that there are a number of things inside the exosomes that interact potentially with cells in the tumor microenvironment,” he added. “Then they circulate in the bloodstream and land in other parts of the body.”
So Pollock asked Prakash if there could be an efficient way of extracting these exosomes from a peripheral blood sample to obtain the contents that might be used to diagnose a tumor deep within the body. The microfluidics expert was intrigued.
“I learned that often by the time sarcomas are diagnosed, the disease state is very advanced,” Prakash said. “The value of isolating these circulating biomarkers is earlier detection. Prognosis is better with earlier detection and diagnosis.”
In the past, Pollock had employed ultracentrifugation to isolate exosomes from blood, but it was arduous and expensive. He and Prakash reviewed the literature and realized there might be several different engineering concepts that could be leveraged to improve the process.
Size-based filtration was first, since exosome size is quite specific. Prakash’s previous water treatment research was useful in developing a microfluidic filtration system. Their second area of focus was targeting a surface marker or protein with monoclonal antibodies to attach, secure and extract the exosomes.
Microfluidic device prototype
The duo’s prototype microfluidic device integrates size-based separation followed by immunoaffinity-based capture of extracellular vesicles in one process. They also are exploring the use of electrical charge to enhance the exosome filtering.
Prakash and Pollock have submitted two manuscripts—one of which was published recently in the Journal of Microelectromechanical Systems—demonstrating their device is more effective than ultracentrifugation in terms of time, yield, and purity.
The collaboration is just the latest example of an emerging partnership between the College of Engineering and The Ohio State University Comprehensive Cancer Center – James Cancer Hospital and Solove Research Institute.
“These circulating biomarkers are a very small fraction of the overall constituency of blood,” explained Prakash. “The real engineering challenge is extracting that proverbial needle from a haystack. And how do you sort that out and get the right needle.”
Exploded view of microfluidic channels separated by a nanocapillary array membrane. The dotted line represents the cross-section that was utilized for SEM characterization of the device, as seen inset. Only a portion of captured exosomes may have been connected to the tumor, so capturing as many as possible within a blood sample is critical.
Beyond the manuscripts, the research team is gearing up to submit a proposal. Coincidentally, the National Cancer Institute is now seeking proposals that focus on developing new methodologies to extract exosomes to investigate whether the cargo inside may be applicable as biomarkers for cancer.
“We’re now in a position to really drill down into the engineering concepts of the device,” Pollock said.
He added that while this type of device could be applied to many types of cancers, it is especially advantageous for sarcoma diagnosis.
“After a long operation to remove a confirmed tumor, it is very difficult in scans to differentiate tumor recurrence from post-surgical scarring,” he explained. “But if you can detect something a tumor releases in the bloodstream, that provides you with a higher index of suspicion of what you may be seeing on a scan.
“Instead of relying on repeat scans over months to determine size increase or decrease, we can potentially identify recurrence at a very early point when the total volume of recurrence is small and more amenable to treatment. We’re very excited about the potential.”
Looking ahead, Prakash and Pollock want to build toward a systematic clinical trial. While there is nothing in the prototype device that cannot be used in a clinical trial, Prakash said some optimization would be required.
“It’s been a total partnership,” Pollock said. “None of this would have happened without the mutual interest and opportunities to communicate about possibilities.”
The research team included mechanical and aerospace engineering PhD student Prashanth Mohana Sundaram, and Lucia Casadei, Gonzalo Lopez, Danielle Braggio and Gita Balakirsky from the Comprehensive Cancer Center.
This blog originated as a press release from Duke Health. Thanks to them for allowing us to repost it here.
DURHAM, N.C. – A team of Duke Health scientists have identified biomarkers that accurately identify numerous viral infections across the clinical stages of disease, advancing a potential new way to guide treatment, quarantine decisions, and other clinical and public health interventions in the setting of endemic and pandemic infectious diseases.
The blood-based test uses a gene expression assay to correctly predict nine different respiratory viral infections including influenza, enterovirus, adenovirus, and coronaviruses known to cause common colds. It shows the body’s genes responding to a pathogen before symptoms are present.
As testing for the coronavirus continues throughout the United States, researchers have been closely watching results, particularly reported rates of false negatives.
According to the Radiological Society of North America, a reported 40 to 70 percent of coronavirus tests from throat swab samples returned false negatives at the onset of the epidemic. Given the highly infectious nature of this particular coronavirus, individuals receiving false negative results — told they do not carry the virus when in fact they do — could continue to infect others.
“It is very concerning,” said Hsueh-Chia Chang, the Bayer Professor of Chemical and Biomolecular Engineering at the University of Notre Dame. “In an overcrowded hospital, where there is only room to quarantine the COVID-19 carriers, false negatives would mean some carriers can continue to infect other patients and healthcare workers. This, unfortunately, is also true for other infectious viral diseases such as dengue and malaria, when there is an epidemic. False negatives are usually not an urgent problem, when every symptomatic patient can be quarantined and there are fewer people to infect — until an epidemic overcrowds our hospitals and we have only enough space to sequester the carriers.”
At Notre Dame, Chang’s research lab focuses on the development of new diagnostic and micro/nanofluidic devices that are portable, sensitive and fast. His work includes diagnostics with applications to DNA/RNA sensing. Current coronavirus tests are RNA-based.
Chang said technology his lab developed for other uses could easily be extended to apply to testing for the coronavirus.
Flow cytometry (FC) is a powerful method for counting single cells and measuring their molecular components. There is increasing interest in applying flow cytometry to the analysis of extracellular vesicles (EV), but EVs are orders of magnitude smaller than the cells for which FC instruments and protocols were originally designed. To catalyze the development of new instruments and assays for EV flow cytometry, three scientific societies came together to form the EV Flow Cytometry Working Group (evflowcytometry.org):
ISEV, the International Society of Extracellular Vesicles
ISAC, the International Society for Advancement of Cytometry, and
ISTH, the International Society for Thrombosis and Haemostasis.
The working group first performed two standardization studies, distributing standards and samples to EV-FC laboratories worldwide to enable an objective comparison of methods, instruments, controls, and analytical tools. Those initial studies led to the realization that a standard framework for reporting experimental results is essential.
Illinois researchers developed a method to detect microRNA cancer markers with single-molecule resolution, a technique that could be used for liquid biopsies.
From left: Taylor Canady, postdoctoral scholar; Andrew Smith, professor of bioengineering; Nantao Li, graduate student; Lucas Smith, postdoctoral scholar; and Brian Cunningham – professor of Electrical and Computer Engineering; director of Micro and Nanotechnology Laboratory. Photo by L. Brian Stauffer
Thanks to the University of Illinois News Bureau for allowing us to share this article here.
CHAMPAIGN, Ill. — A fast, inexpensive yet sensitive technique to detect cancer markers is bringing researchers closer to a liquid biopsy – a test using a small sample of blood or serum to detect cancer, rather than the invasive tissue sampling routinely used for diagnosis.
Researchers at the University of Illinois developed a method to capture and count cancer-associated microRNAs, or tiny bits of messenger molecules that are exuded from cells and can be detected in blood or serum, with single-molecule resolution. The team published its results in the Proceedings of the National Academy of Science.
Thanks to Eileen Leahy from Elsevier and Chhavi Chauhan, Director of Scientific Outreach for the Journal of Molecular Diagnostics, for sharing this post here.
A novel non-invasive technique may detect human papilloma virus-16, the strain associated with oropharyngeal cancer, in saliva samples, reports The Journal of Molecular Diagnostics.
Philadelphia, December 13, 2019 – Unfortunately, cancers that occur in the back of the mouth and upper throat are often not diagnosed until they become advanced, partly because their location makes them difficult to see during routine clinical exams. A report in The Journal of Molecular Diagnostics, published by Elsevier, describes the use of acoustofluidics, a new non-invasive method that analyzes saliva for the presence of human papilloma virus (HPV)-16, the pathogenic strain associated with oropharyngeal cancers (OPCs). This novel technique detected OPC in whole saliva in 40 percent of patients tested and 80 percent of co published by Elsevier, describes the use of acoustofluidics, a new non-invasive method that analyzes saliva for the presence of human papilloma virus (HPV)-16, the pathogenic strain associated with oropharyngeal cancers (OPCs). This novel technique detected OPC in whole saliva in 40 percent of patients tested and 80 percent of confirmed OPC patients.
“OPC has an approximate incidence of 115,000 cases per year worldwide and is one of the fastest-rising cancers in Western countries due to increasing HPV-related incidence, especially in younger patients. It is paramount that surveillance methods are developed to improve early detection and outcomes,” explained co-lead investigator Tony Jun Huang, PhD, Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC, USA.
“Considering these factors, the successful detection of HPV from salivary exosomes isolated by our acoustofluidic platform offers distinct advantages, including early detection, risk assessment, and screening,” added Dr. Huang. This technique may also help physicians predict which patients will respond well to radiation therapy or achieve longer progression-free survival.
This blog post was adapted from a press release by the Baylor College of Medicine. See this related video from the ERCC Webinar Series for a discussion of the exceRpt pipeline used in the analysis presented here.
Scientists have improved their understanding of a new form of cell-cell communication that is based on extracellular RNA (exRNA). RNA, a molecule that was once thought to function only inside cells, is now known to participate in a cell-cell communication system that delivers messages throughout the body. To better understand this system, the Extracellular RNA Communication Consortium (ERCC), which includes researchers from Baylor College of Medicine, created the exRNA Atlas resource, the first detailed catalog of exRNAs in human bodily fluids. They also developed web-accessible computational tools other researchers can use to analyze exRNAs from their own data. The study (Murillo, Thistlethwaite, et al. 2019), published in the journal Cell, contributes the first ‘map of the terrain’ that will enable scientists to study the potential roles exRNA plays in health and disease.
“About 10 years ago, scientists began discovering a new communication system between cells that is mediated by exRNA,” said corresponding author Dr. Aleksandar Milosavljevic, professor of molecular and human genetics and co-director of the Computational and Integrative Biomedical Research Center at Baylor College of Medicine. “The system seems to work in normal physiological conditions, as well as in diseases such as cancer.”
The Milosavljevic lab worked with other members of the ERCC to analyze human exRNAs from 19 studies. They soon realized that the system was significantly more complex than initially assumed. Due to that unanticipated complexity, existing laboratory methods failed to reproducibly isolate exRNAs and their carriers. To help create the first map of this complex system of communication, Milosavljevic and his colleagues used computational tools to deconvolute the complex experimental data. Deconvolution refers to a mathematical method and a computational algorithm that separates complex information into components that are easier to interpret.
“Using computational deconvolution, we discovered six major types of exRNA cargo and their carriers that can be detected in bodily fluids, including serum, plasma, cerebrospinal fluid, saliva, and urine,” said co-first author Oscar D. Murillo, a graduate student in Baylor’s Molecular and Human Genetics Graduate Program working in the Milosavljevic lab. “The carriers act like molecular vessels moving their RNA cargo throughout the body. They include lipoproteins – one of the major carriers is High-Density Lipoprotein (HDL or the “good cholesterol”) – a variety of small protein-containing particles, and small vesicles, all of which can be taken up by cells.”
The researchers found that the computational method helps reveal biological signals that could not previously be detected in individual studies due to the naturally complex variation in the biological system. For example, in an exercise challenge study their computational approach revealed differences before and after exercise in the proportions of the exRNA cargo in HDL particles and vesicles in human plasma.
“Exercise increased a proportion of RNA molecules involved in regulating metabolism and muscle function, suggesting adaptive response of the organism to exercise challenge,” Milosavljevic said. “This finding opens the possibility that in other conditions, both in health or disease, the computational method might identify signals that could have physiological and clinical relevance.”
To help researchers around the world with their analyses, Murillo, Milosavljevic and their colleagues have made a computational tool available online (https://exRNA-Atlas.org).
“We anticipate that it will take a combination of scientific knowledge, enhanced experimental techniques to isolate cargo and carriers in bodily fluids, and advanced computational methods to deconvolute and interpret the complexity of the exRNA communication system,” Murillo said.
Other contributors to this work from Baylor College of Medicine include William Thistlethwaite, Matthew E. Roth, Sal Lakshmi Subramanian, Rocco Lucero, Neethu Sha, and Andrew R. Jackson. See the full article for details about the numerous other contributors from the consortium.
This work is part of the NIH Extracellular RNA Communication Consortium paper package and was supported by the NIH Common Fund Extracellular RNA Communication Program (grant U54 DA036134).
Reference Murillo OD, Thistlethwaite W, et al. exRNA Atlas analysis reveals distinct extracellular RNA cargo types and their carriers present across human biofluids. (2019) Cell177:463-477. doi: 10.1016/j.cell.2019.02.018. PMID: 30951672.