NEW YORK (GenomeWeb) – Startup mFluiDx — a portmanteau of "microfluidics" and "diagnostics" — is developing an inexpensive, sample-to-answer, self-digitizing quantitative microfluidic diagnostics platform that does not require an external instrument to run.
The mFludiX diagnostic is able to process whole blood with on-chip sample prep and requires simple external heating and a simple optical reader, similar to a DNA gel reader, to obtain quantitative results, mFluiDx co-founder Charlie Yeh said in an interview.
Scientists from the company described the underlying technology last month in Science Advances, also showing its performance on blood samples spiked with methicillin-resistant Staphylococcus aureus DNA.
The device is called the "self-powered integrated microfluidic point-of-care low-cost enabling" chip, or Simple Chip. It integrates microfluidic patterning of reagents, separation of plasma from whole blood, digital plasma distribution into hundreds of droplets, and vacuum-driven processing with an integrated vacuum battery. It uses recombinase polymerase amplification, available commercially from Alere subsidiary TwistDx, for isothermal digital amplification, providing sample-to-answer detection in about 30 minutes.
The firm chose RPA because it is commercially available and is one of the fastest isothermal methods on the market, Yeh said, with a high tolerance for plasma samples. It has not tried any other isothermal methods but is open to collaboration. Heating at 40° C for 30 minutes is required, but mFluiDx has been experimenting with doing this using hand warmers, heat packs, and incubators. Other researchers have found that body heat is enough to reliably run the RPA reaction, as previously reported.
Other point-of-care and near-patient diagnostics that are currently commercially available or in development are typically cartridge-based and require a platform to provide heat for reactions, as well as internal systems to drive pumps, valves, and other liquid handling. They also tend to demand either already-extracted nucleic acids or very simple sample types. Such a system might be better described as a "lab around a chip" rather a "lab on a chip," Yeh said.
mFluiDx ultimately intends to move its products into the space currently occupied by dipstick technologies, such as rapid immunoassays, Yeh said, with a price that is several hundred times lower than current commercial molecular options for point of care.
The Simple Chip is based on research done at the University of California, Berkeley by the lab of Luke Lee, where Yeh did his doctoral work. That research was supported by $2.5 million in funding from the Bill and Melinda Gates Foundation and the Defense Advanced Research Projects Agency (DARPA), Yeh said.
So far, three patents have come from the project. Berkeley coordinated the patenting, providing mFluiDx with exclusive licenses, and it has also provided office and lab space, resources, and mentoring support through its CITRIS accelerator program, Yeh said, in exchange for equity.
The firm has also been supported by seed funding from venture capital, and is part of the IndieBio Accelerator in the Bay area, which is providing lab and office space and a biotech-specific accelerator program, as well as the QB3 network.
In addition, support has come from a Taiwanese government program that aims to build collaborations between Taiwanese industry and the Bay area ecosystem, Yeh said. "They are trying to invest in young founders who have a Taiwanese affiliation or who are willing to set up collaborations between Taiwanese industries and Silicon Valley."
These collaborations may provide an important boost to the firm in terms of scalable microfluidic manufacturing, which has proven to be a challenging bottleneck for some device makers. "Taiwan has very advanced semiconductor manufacturing capabilities which can be transformed for microfluidic fabrication," he noted.
The company currently has an alpha prototype of its assay system, and is very carefully weighing its options as to which infectious disease targets it should go after first. "This is actually a big business decision, because it is a molecular platform technology, like a PCR machine — you just change the primers for different organisms you want to look at — but the question is, what is the most efficient go-to-market strategy," Yeh said.
Toward this end the firm is participating in the National Science Foundation's I-Corps program, which provides "real-world, hands-on, immersive learning about what it takes to successfully transfer knowledge into products and processes," according to the website. I-Corps can serve as a path to Small Business Innovation Research funding and, ultimately, product launch. The rigorous program requires that companies consult with 150 end users and business decision makers in order to find a product-market fit, and it provides training for commercialization. Yeh said mFluiDx has already completed the regional process and is moving on to the national process as part of the program.
The firm is also planning to make its chip available as a research tool for others to use as a simple, low-cost alternative to a PCR machine, in addition to developing primer and probe sets for specific diseases, Yeh said.
Yeh said the firm is hoping to have a product on the market in one to two years, but exact timing will depend on fundraising. It is currently doing small-scale testing with patient samples.
Commercially, mFluiDx considers itself to be in the point-of-care molecular diagnostics space for infectious diseases, potentially putting it in the same arena as the Alere i and Alere q platforms, Roche Liat, Quidel Solana, Cepheid Omni, or the Spartan Cube, as well as numerous POC MDx platforms and systems being developed by researchers in other industry and academic settings.
The mFluiDx system, however, will be less costly because it will not require an instrument to run the assay, Yeh said. "We are able to drive all the fluids with vacuum gas diffusion control," he said, since the device is stored in a vacuum pouch and opening the pouch activates the vacuum within the chip, which sustains vacuum pressure for three hours.
Point-of-care microfluidic diagnostics have been looming on the horizon for some time, but there has not been a successful commercial product. For automated platforms, Yeh attributes this to the cost of the cartridges and the systems to drive them. Automated systems are simpler to use, however, whereas less automated systems typically require multiple manual steps.
"I think the successful point-of-care microfluidic that will be mass adopted will have to solve these problems of cost and simplicity," he said, adding, "It is going to come someday ... it's just a matter of time."